Abstract: A centrifugal separator comprises a follow rotor which is formed with a row of pores arranged circumferentially of the rotor and perforated, cylindrical film detachably received on the inner peripheral surface of the rotor. A mass of a semifluid material positioned within the film is splashed on to the inner surface of the film by a centrifugal force so that the liquid content of the material is passed through the film. The film is radially contracted by the liquid pressure developed between the film and the inner peripheral surface of the rotor and forms a cylindrical interstice between the film and the rotor, providing an additional filter medium through which the liquid is filtered and withdrawn from the pores. The rotor may be closed throughout its area and have a free longitudinal end from which to allow the liquid to withdraw. The centrifugal separator finds an application as a juice extractor if provided with a grating disc.