The execution of a Jewish industrialist, one of the latest victims of Islamic revolutionary courts, sent chills through Iran's 80,000-member Jewish community today as the courts vowed to continue their "cleansing of society."

Jewish merchants and participants in a synagogue gathering in downtown Tehran expressed nervousness and fear about the execution by an Islamic firing squad of Habib Elghanian, a multimillionaire plastics magnate accused among other things of "contacts with Israel and Zionism."

In a lengthy indictment, Elghanian, 61, was accused of spying for Israel, promising Israeli leaders the support of Iranian Jews, "massacring Palestinians," corruption and promoting "economic imperialism" through his plastics industry.

What, if any, evidence of these charges was presented in court was not immediately disclosed. Jewish sources said Elghanian's main "crime" seemed to be his large financial contributions to Israel.

They said that if this becomes a capital offense in Iran, many other Jews here may be in trouble. The execution could prompt mass departures from Iran similar to the Jewish exodus before the revolution that overthrew the shah's monarchy in February.

In Jerusalem, Israeli Prime Minister Menachem Begin denounced the execution. Speaking in the Israeli parliament, he urged the world not to remain silent following "the executions of this murderous regime." He said Elghanian "was a good Zionist and one who helped Israel."

[State Department spokesman Hodding Carter reiterated U.S. criticism of the secret and summary nature of the trials and executions in Iran. He went on to say that "it is disturbing that Mr. Elghanian was a member of a minority community."]

The latest victims of the Islamic courts-eight in number-also included a wealthy Moslem casino and amusement park owner; a former information minister who was also a top official of SAVAK, the shah's secret police; a SAVAK physician and alleged torture specialist; two SAVAK "anti-sabotage committee" officials and two provincial policemen.

The eight executions brought the number of those shot so far to at least 200.

Elghanian was the first Iranian Jew to be executed since the revolutionary trials began in late February. He and the Moslem entrepreneur, Rahim Ali Khorram, were also the first businessmen to die before the firing squads.

Both were said to be friends of deposed Shah Mohammad Reza Pahlavi.

Other Jews are reportedly being held in prisons by revolutionary authorities on as yet unspecified charges. Among them is said to be at least one Jewish member of parliament during the shah's rule.

Before the February revolution clamped restrictions on departures, more than 12,000 Iranian Jews left the country, many of them permanently.

Reacting to mounting foreign criticism of their drumhead justice, Tehran's revolutionary courts defended the executions as "answering the demands of the peoplee."

The statement, the first by the revolutionary tribunals, made it clear that the latest wave of wholesale executions is intended mainly as a warning to "counter-revolutionaries" and as a sop to domestic public opinion to compensate for failures on other fronts. Most of former high officials under the shah.

Calling the executed men "putrid vestiges of the old regime," the courts said human rights appeals, notably from the United States, "will not divert the revolution from its true path."

To grant a general amnesty, the statement said, "would be to allow counter-revolutionaries strength when the blood of the martyrs has still not been cleansed from the city's walls."

The courts claimed that since the arrests of suspects had abated, counter-revolutionaries were "becoming bolder and coming out of their holes." The statement added that if the courts do not or cannot carry out death sentences, "the people will try to seek revenge and chaos will ensue."

The statement also referred to the two businessmen executed early today as "agents of capitalism." It added:

"The execution of these leeches is, in fact, the execution of dependent capitalism and the best guarantee that this system will be destroyed."

The communique thus appeared to condemn efforts by the government to restrict the arrest of suspects and promote at least a limited amnesty for political prisoners. It also raised fears that more "capitalists" could face the firing squads.

Ayatollah Ruhollah Khomeini, currently Iran's de facto chief of state, has repeatedly promised that religious minorities would be protected under the new government.Yet, adherents of Jewish, Christian, Bahai and other minority faiths have expressed wariness and anxiety over the course of the Islamic fundamentalist movement.

Khorran was accused of aiding and abetting murder and assault, abusing power, establishing brothels and gambling dens, receiving support from foreigners and destroying national sovereignty.

The standard charges of "corruption on earth" and "warring against God and his emissaries" were also used for several of the eight defendants, two of whom were convicted in the provinces.

According to a Tehran newspaper, witnesses at Khorram's trial claimed he once threw a poor man into a lion's cage in his amusement park and provided Philippina prostitutes for members of the royal family and other dignitaries.

Following the news of the executions, Prime Minister Mehdi Bazargan criticized "tyranny" in a broadcast speech, but it was not clear whether he was referring to the latest shootings.

"As we staged a revolution against tyranny, we should not be tyrants outselves," he said. "We should be just the opposite." CAPTION: Picture, Habib Elghanian appears before an Islamic court before being sentenced to die. AP