A fusing unit of an image forming apparatus is capable of controlling fusing pressure according to detailed types of printing medium without deteriorating printing speed. A first roller rotates about a first rotation shaft CR1. A second roller rotates in contact with the first roller about a second rotation shaft CR2 and is movable along the outer circumference of the first roller. A moving unit relocates the second roller according to a type of printing medium. A pressing unit presses the second roller toward the first roller by applying different pressures according to a position of the second roller with respect to the first roller.