The present invention relates to a method of producing a collagen membrane that has particular mechanical properties. In particular, the present invention relates to a method A of producing a collagen membrane comprising the steps of (i) isolating a collagen-containing tissue and incubating same in an ethanol solution; (ii) incubating the collagen-containing tissue from step (i) in a first solution comprising an inorganic salt and an anionic surfactant in order to denature non-collagenous proteins contained therein; (iii) incubating the collagen-containing tissue produced in step (ii) in a second solution comprising an inorganic acid until the collagen in said material is denatured; and (iv) incubating the collagen-containing tissue produced in step (iii) in a third solution comprising an inorganic acid with simultaneous mechanical stimulation for sufficient time to enable the collagen bundles in said collagen-containing tissue to align; wherein the mechanical stimulation comprises applying tension cyclically to the collagen-containing tissue.