MOSCOW, SEPT. 11 -- The KGB security police today opened the door of the infamous Lubyanka prison, inviting Soviet and foreign reporters to what was billed as the first in a regular series of press briefings.

"Glasnost {openness} has arrived within the walls of the KGB," announced the head of the KGB's new Center for Public Affairs, Gen. Alexander Karabainov, welcoming journalists to a new press center and museum devoted to the agency's counterespionage triumphs.

The public affairs center is located at the front of the Lubyanka, overlooking the statue of Felix Dzherzhinsky, founder of the Soviet police. Access is by a special elevator programmed to stop only at the third floor, despite a set of mysterious unmarked buttons.

Today's inauguration of the center forms part of a campaign by the KGB to humanize its gruesome image -- tens of thousands of innocent people were tortured in the '30s and '40s -- and find a niche for itself in a new, more democratic society.

The openness drive has been greeted with skepticism by radical politicians and even some former members of the KGB.

A former KGB officer commented later, "It's just a public relations stunt. You can't just open up a few rooms and say you have opened up the KGB." The former officer, Oleg Kalugin, the onetime ranking KGB official in Washington, was stripped of his general's rank and medals earlier this year after denouncing the slow pace of reform in the agency.

At today's press conference, KGB officials formally condemned the period of Stalinist terror, during which millions of people lost their lives, as a time of "lawlessness."

But they took a more ambiguous attitude toward the repression of dissidents during the '70s.

"The KGB was obliged to enforce the law" then in effect, Karabainov said.

But Kalugin commented, "That is essentially the same defense that the senior Nazis gave at the Nuremburg trials."