Provided is a collagen sponge having a compressive strength (stress) equivalent to that of the tissue to be implanted, having no irregularity in structure and stress, and having a pore structure for cell infiltration. The collagen dispersion, solution, or mixture of collagen having a collagen concentration of 50 mg / ml or more is insolubilized after lyophilization, has a stress of 10 to 30 kPa at a strain of 10% load, and has a pore structure on the surface and inside A collagen sponge having a pore having an average diameter in the range of 50 to 400 m and a standard deviation of the pore diameter of 80% or less of the pore average diameter has a compressive strength (stress) equal to that of the tissue to be implanted It has a pore structure to have uneven structure and stress and to infiltrate cells.埋植する組織と同等の圧縮強度(応力)を有し、構造及び応力にむらがなく、かつ細胞が浸潤するためのポア構造を有するコラーゲンスポンジの提供。 コラーゲン濃度が50mg/ml以上であるコラーゲンの分散液、溶液、又はその混合物を凍結乾燥の後、不溶化処理を行い、ひずみ10%負荷時に10~30kPaの応力を持ち、表面及び内部にポア構造を持ち、ポアの平均直径が50~400μmの範囲であり、並びにポアの直径の標準偏差がポアの平均直径の80%以下であるコラーゲンスポンジは、埋植する組織と同等の圧縮強度(応力)を有し、構造及び応力にむらがなく、かつ細胞が浸潤するためのポア構造を有する。
