The present invention relates to a 2-phenylthiophene derivative or a salt thereof, wherein the thiophene ring is substituted with a carboxyl group or the like and the benzene ring has an electron-withdrawing group such as a cyano group and an electron-donating group such as a substituted alkoxy group at the same time. Since the compound of the invention has good xanthine oxidase-inhibitory action and uric acid-lowering action and does not have a structure derived from nucleic acid, the compound has advantages of high safety and excellent effects as compared with conventional compounds and is useful as a therapeutic or preventive agent for hyperuricemia, gout, inflammatory bowel diseases, diabetic kidney diseases, diabetic retinopathy, or the like.