A sheet-form structure of expandable thermoplastic resin is provided which is capable of undergoing a pseudo-one-dimensional expansion in its thickness direction and which enables manufacture of thermoplastic resin foams having reduced variations in thickness and weight precisions, increased compressive strength, and excellent properties such as surface smoothness. A method of manufacturing the sheet-form structure, as well as such thermoplastic resin foams, are also provided. A sheet-form structure 1 of expandable thermoplastic resin including granules 2 of expandable thermoplastic resin arranged generally uniformly for integral connection thereof through a thin film 3 of expandable thermoplastic resin. A thermoplastic resin foam including a continuous, thermoplastic resin foam layer, a number of highly-expanded, thermoplastic resin portions provided on at least one surface of the continuous foam layer, and slightly-expanded, thermoplastic resin thin films for covering outer surfaces of respective highly-expanded portions.