By allowing serum or plasma samples collected from humans to react with laminin-1 or a fragment thereof, and then determining whether or not anti-laminin-1 antibody, an auto-antibody against laminin-1, in the sample bound to laminin-1 to detect anti-laminin-1 antibody in the sample, gynecology-related diseases such as habitual abortion, sterility, infertility, and endometriosis can be diagnosed.