The present invention proposes a fixing apparatus which can properly adjust the fixing ability and the curvature separation ability based on sheet quality, and an image forming apparatus having the same fixing apparatus. This fixing apparatus, which forms images through fixing the toner images on the sheet, includes an endless belt which is pressure-contacted against the fixing roller, a pressure applying member which makes the endless belt to come into pressure-contact with the fixing roller to form a pressure-contact region, and a separation member which is integral to the pressure applying section and is depressed into the fixing roller, wherein when the pressure applying member swings in a direction in which an area of contact between the endless belt and the fixing roller increases, the separation member swings in a direction in which a depressed depth of the endless belt into the fixing roller decreases, and vice versa.