Abstract: A collagen is extracted and produced from a raw fish skin through the steps: a salt admixing step for admixing a salt (e.g. NaCl, KCl or the like) with a raw fish skin so as to allow non-collagen substances or portions (including fats and other tissue portions than a collagen portion) to be removed from the fish skin, while simultaneously degreasing and deodorizing the skin under the salt effect; a salt removal step for causing the admixed salt and non-collagen substances or portions to remove from the skin, achieving the fats removal and deodorization; a collagen extraction step for extracting a collagen (gelatinous) from the thus-treated skin; and a filtration step for filtering and refining the extracted collagen so as to obtain a refined collagen. The refined collagen may be dried and solidified. Thus, since the inexpensive salt is used for effective removal of non-collagen substances or portions to obtain a collagen portion, the method itself is simplified and economical.