[PROBLEMS]To provide a thin film-shaped porous bioabsorbable material that is a dense structure in which the pore size average is small and the pore size is uniform and which further has a large maximum stress, in particular, a porous bioabsorbable material extremely useful as an adhesion preventing material.[MEANS FOR SOLVING PROBLEMS]A porous bioabsorbable material characterized by being formed of a porosified bioabsorbable polymer which is obtained in a manner that a bioabsorbable polymer is gelled with a good solvent and a poor solvent, compatible with each other, for the bioabsorbable polymer and the gelled bioabsorbable polymer is subjected to freeze-drying to be porosified and a method of producing the porous bioabsorbable material, the method being characterized in that a bioabsorbable polymer is gelled with a mixed solvent composed of a good solvent and a poor solvent, compatible with each other, for the bioabsorbable polymer and the gelled bioabsorbable polymer is subjected to freeze-drying to be porosified.
