The present invention provides a medicament exhibiting excellent retinoic acid receptor agonism. A Carboxylic acid derivative having a fused ring which is represented by the following formula or a pharmacologically acceptable salt thereof: {wherein the symbol represents a single bond or a double bond; X, Y, Z, P, Q, U, V and W are each a group represented by the formula: —O— or —S—, or a group represented by the formula: [wherein Rk (k: 1 to 8) is hydrogen, halogeno, optionally substituted lower alkyl or the like, with either of R7 and R8 being a group represented by the formula: (wherein A and B are each independently an optionally substituted aromatic hydrocarbon ring or an optionally substituted unsaturated heterocycle; and D is optionally protected carboxyl)]}.