An NFAT signal inhibitor and the like are provided.An NFAT signal inhibitor and the like, containing, as an active ingredient, at least one compound selected from the group consisting of a coumarin derivative represented by formula [where in the formula (I), R1 and R2, which may be identical with or different from each other, each represent a hydrogen atom or a group represented by formula (II) (where in the formula (II), R3 represents a linear or branched alkyl or alkenyl group having 1 to 20 carbon atoms)] and pharmacologically acceptable salts thereof.