A fixing device includes a heating belt, a pressing roller, a pressing member and a cap. The pressing member faces an inner circumferential face of the heating belt via a lubricant. The cap is rotating together with the heating belt. The cap has a disk part, a cylindrical part, a gear and a hole part. The cylindrical part has an inner circumferential face coming into contact with the outer circumferential face of the heating belt. The gear is formed integrally with an outer face of the disk part. The hole part penetrates from the inner circumferential face of the cylindrical part to a face between adjacently disposed teeth of the gear. The lubricant flowed from the inner circumferential face of the heating belt to the outer circumferential face of the heating belt flows to a tooth surface of the gear through the hole part.