A separator or a packaging material is provided, comprising a thermoplastic plastic film at least one surface of which is a matte surface or an embossed surface having a surface roughness (Ra) of not larger than 1/2 of the thickness of the film. The thermoplastic film may have a release treatment layer on the whole or part of a surface. The separator or packaging material is useful as a separator for pressure-sensitive adhesive articles and disposable articles or as a packaging material for packing foods, pressure-sensitive adhesive articles and sanitary articles. In particular, the separator is suitably used as a separator for a disposable diaper and a sanitary napkin, and also the packaging material is suitably used as a package for a sanitary napkin.