Five million Japanese women have entered the work force in the past 13 years, but many suffer from sex discrimination despite government efforts to protect them, an official report said Friday.

Prime Minister Noboru Takeshita's office said the number of women in the work force has increased from 12 million in 1975 to 17 million in 1988 - roughly 40 percent of the total work force.However, an official for the Takeshita's office, Kiyoko Fujii, said few women get responsible positions in management or as specialists, despite Japan's 1981 Equal Opportunity Employment Law. For example, only 29 women are representatives in the 764-member parliament, she said.

More than 63 percent of all working women who responded to a government survey in 1987 complained of unequal treatment, said a report by Take-shita's office.

Although many private companies have begun providing equal opportunities for female job-seekers, women face discrimination in promotions, pay and working conditions, Fujii said.

She also charged that "general position" examinations for promotions may discriminate against women. The test does not violate the 1981 law because it involves promotion, not hiring, she said.

Lack of child care facilities at work sites is also a big obstacle for mothers who want to keep working. "Many companies don't allow mothers to bring their children to work," she said.

In a 30-minute video at a government news conference Friday, several career women with responsible positions were introduced.

"Japanese society is still ruled by men, and the roles of each sex are stubbornly fixed. More women should take part in decision-making processes in society - especially in politics - to share responsibilities equally with men," feminist Yoko Nuita said in the video.