A sheet-like fibrous assembly having an inelastic stretchability is intermittently joined to at least one surface of an elastically stretchable sheet. The elastic sheet is elastically stretchable at least 80% in one direction and the fibrous assembly is curved between each pair of binding spots adjacent to each other on the elastic sheet so as to be stretchable in the one direction and comprises ethylene/propylene copolymer, ethylene/propylene/butene copolymer or a mixture of two or more of these copolymers at 100.about.10% by weight.