To provide a novel aromatic ring compound capable of having a GPR40 agonist activity and a GLP-1 secretion promoting action. Formula (I): [Each symbol in the formula is as described in the specification. ] The compound represented by the formula or a salt thereof may have a GPR40 agonist activity and a GLP-1 secretion promoting action, and may include cancer, obesity, diabetes, hypertension, hyperlipidemia, heart failure, diabetic complications, and metabolic syndrome. , It may be useful for prevention and treatment of sarcopenia and the like, and may have excellent medicinal effect. [Selection diagram] NoneGPR40アゴニスト活性およびGLP-1分泌促進作用を有し得る新規な芳香環化合物を提供すること。式(I):[式中の各記号は、明細書に記載の通りである。]で表される化合物またはその塩は、GPR40アゴニスト活性およびGLP-1分泌促進作用を有し得、癌、肥満症、糖尿病、高血圧症、高脂血症、心不全、糖尿病性合併症、メタボリックシンドローム、筋肉減少症等の予防・治療に有用であり得、かつ優れた薬効を有し得る。【選択図】なし