A 27-year-old Minneapolis man was sentenced to two year's probation in federal court yesterday after pleading guilty to using faked Internal Revenue Service credentials to enter the U.S. Courthouse here and to use copying machines in the federal prosecutors' office.

Gerald B. Wolfe, who was described as a member of the Church of Scientology when the incidents occurred last summer, also must donate 100 hours of his time to a community service program to be designated later.

Assistant U.S. Attorney Garey Stark of the fraud division has asked that Wolfe be fined for the three entries which Stark said have not been explained to the government's satisfaction. Stark said he disbelieves Wolfe's contention that he and another Scientology official faked the credentials as a lark when they are under the influence of alcohol.

Stark said he is also suspicious because Wolfe refused to plead to a lesser charge of misdemeanor involving the incidents, but instead decided to enter his plea to the five-year-penalty felony charge on which he was sentenced yesterday.

The other Scientology member alleged to have illegally entered the courthouse building has been a fugitive for the past year, Stark said.

The Church of Scientology has brought numerous lawsuits against the government for alleged harrassment, and six of those lawsuits were being defended by the U.S. Attorney's Office when the entries occurred here.

Stark said Scientology documents filed in those lawsuits have mentioned the possibility of members of the church infiltrating IRS and U. S. attorney's office in other parts of the country.