[Problems] A useful compound which can be used as a pharmaceutical, in particular, an agent for treating peripheral arterial occlusive disease is provided.[Means for Solution] The present inventors have conducted extensive studies on EP4 receptor agonists, and as a result, have found that a novel pyridone compound, in which a group having an acidic group is substituted at the 1-position of the pyridone ring, the 6-position is bonded with an aromatic ring group via a linking part, and the linking part contains a nitrogen atom, has an excellent EP4 receptor agonistic action, thereby completing the present invention. Since the compound of the present invention has an excellent EP4 receptor agonistic action, it is useful as a pharmaceutical, in particular, as an agent for treating peripheral arterial occlusive disease.