An image forming apparatus includes a fixing device and a cooling device provided on a side downstream of the fixing device with respect to a sheet feeding direction. The cooling device includes a first unit including a first belt and a first roller, a second unit including a second belt for forming a nip in cooperation with the first belt, a heat sink and a second roller, and a driving motor for rotating the first roller and the second roller. The second unit is movable between a contact position where the first belt and the second belt are in contact with each other so as to form the nip and a separated position where the first belt and the second belt are in separation from each other so as to release the nip.