 In 1951, she started working at the Swedish National Heritage Board and the Swedish History Museum, where she was Head Antiquarian in 1972-87, and in 1987 she became Sweden's first female National Antiquarian, a position she held until 1993.In 1967-75, Biörnstad was a member of the Museum and Exhibition Expert Committee ("1965 års musei- och utställningssakkunniga", MUS 65).The project caused much debate and resulted in giving increased responsibility to the County Administrative Boards for the counties' local cultural heritage.