An image forming apparatus includes an image forming device for forming a toner image on a recording medium and a fixing device for fixing the toner image formed on the recording medium by applying heat and pressure to the recording medium. In the fixing device, an endless belt, having flexibility, moves to apply heat to the recording medium. A metal thermal conductor, having a pipe shape and provided inside a loop formed by the endless belt, guides the moving endless belt. A heat source heats the metal thermal conductor. A pressing member presses the metal thermal conductor via the endless belt to form a nip between the endless belt and the pressing member. At the nip, the endless belt and the pressing member nip the recording medium bearing the toner image to apply heat and pressure to the recording medium.