Sound absorbing material for use in rooms inside buildings. The material comprises a continuous polymeric film (11) having smooth surfaces, said film having a thickness (t) of about 0.1 to 0.3 mm. The film is provided with numerous substantially parallel discontinuous microslits (12) with a degree of perforation of from 0.3-3%. The microslits are cut with laser devices to produce a highly smooth and level surface. The film is tensioned in a frame (16) with a level film surface or curved film surface.