WASHINGTON (AP) _ The director of religous affairs for the communist government in Czechoslovakia says his country has freedom of worship and his office has a good working relationship with the Roman Catholic and other faiths.

''The churches are an integral part of our society, today and in the future,'' Vladimir Janku, the Czech official, told a gathering of U.S. Roman Catholics, Czechoslovak emigres, Congressional staffers, diplomats and journalists Friday.

Janku also dismissed a petition on religious freedom signed by hundreds of thousands of Czechoslovaks the past year as a ''normal'' statement supporting freedom rather than a demand for what is lacking.

President Gustav Husak has invited Cardinal Frantisek Tomasek, the 90-year- old Roman Catholic archbishop of Prague, to participate in drafting the country's next constitution, he said.

Janku defended the continued existence of his office and the government's right to approve appointment of bishops. After years of negotiation, four Roman Catholic bishops were named this year but half the 13 dioceses still lack them.

Janku plans to meet on Monday with Richard Schifter, U.S. assistant secretary of state for human rights, other State Department officials and Congressman Tom Lantos, D-Calif., a native of Hungary who heads the Congressional human rights caucus.

Monday's meetings could determine if the two countries are ready to begin a dialogue on human rights that U.S. Secretary of State James Baker III suggested to Czechoslovakia's foreign minister during their U.N. meeting last month. Earlier in the year, former Deputy Secretary of State John Whitehead said in Prague that human rights would be the key to improving relations with the United States.

Friday's gathering, in the U.S. Capitol complex, was arranged by the Slovak American National Council, an emigre organization that until recently was among the communist government's arch-critics.

The organization's executive director is John Hvasta, a Slovak-American U.S. Navy veteran who spent three years in Czechoslovakia's Leopoldov prison, escaped in 1951, and made his way to the U.S. Embassy in Prague, in one of the celebrated incidents of the cold war.

Hvasta said he was surprised by the new atmosphere, though less than satisfied with some of Janku's answers.

Janku told the gathering that perestroika, or restructuring, has come to Czechoslovakia but in a different form from the efforts in Poland and Hungary to abandon the Leninist model of socialism.

If perestroika means ''dismantling of socialism, we are lagging,'' said Vladimir Janku during a visit late last week. ''Ours is a socialist perestroika.''