A collagen structure characterized by comprising collagen fibers that have an average diameter of 1 to 5 µm, and having a water content of 0 to 15 (w/w)% and a collagen density of 50 to 800 mg/cm3. An acidic collagen solution is neutralized to produce collagen fibers, and then the solution is subjected to filtration or the like to produce crude collagen fibers having a collagen concentration of 12 to 50 (w/v)%. The crude collagen fibers are shaped into a predetermined shape, and the resultant product is dried, thereby producing the collagen structure. Since collagen fibers composed of associated collagen molecules is used as a material for the collagen structure, the collagen structure has excellent cell invasiveness. Further, since the collagen density in the collagen structure is equivalent to that in a collagen tissue in a living body, the collagen structure can exhibit excellent tissue regeneration performance when filled into a lost part in a living body, and therefore can be used suitably as an artificial material for regenerative medicine or the like.
