An image forming apparatus includes a transfer unit for transferring a toner image onto a sheet, a fixing device for fixing the image, the fixing device including a belt, a pressure element for pressing against the belt, a heating member on the belt including a heat generating element and electrodes on both sides of the heat element in a sheet conveyance direction and connected to the heat element, and an adjustment mechanism for moving one of the heating member and the pressure element in a manner to move the one closer to or away from the other, and a controller for controlling the adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.