Provided is a detergent having a high detergency against corneum-derived stains and a method for evaluating the ability of an enzyme to degrade corneum-derived stains. The detergent a M23A subfamily protease as an active ingredient. The method for evaluating the ability of the enzyme to degrade corneum-derived stains comprises obtaining the degrading activities of the test enzyme on a reference peptide and one or more substrate peptides and evaluating the ability of the test enzyme to degrade corneum-derived stains based on the degrading activities of the test enzyme on the reference peptide and the substrate peptide, wherein the reference peptide is GGGGG or GGGG, the one or more substrate peptides are selected from the group consisting of GGGXG, GXGGG, GGXG, and GXGG, and X is any amino acid residue other than glycine.