To provide a collagen sponge excellent in mechanical strength and a production method for the collagen sponge. A collagen sponge including a porous construct having a pore structure, the collagen sponge having a tensile strength of 1 N or more and 5 N or less in every direction including a length direction and a width direction. The collagen sponge may be produced by a production method including the following steps: (1) a step of subjecting a collagen solution obtained by mixing collagen and a solvent to stirring and deaeration treatment； (2) a step of subjecting the collagen solution to freeze-dry treatment； and (3) a step of subjecting a dried collagen product after the freeze-dry treatment to insoluble treatment.
