The fixing device includes: a fixing belt that is heated by a heater lamp; a pressure roller that makes contact with the fixing belt; a fixing pad that sandwiches the fixing belt from the inner side of the fixing belt and is arranged opposing the pressure roller, and which forms a nip portion between the fixing belt and the pressure roller; a sliding sheet provided between the fixing pad and the fixing belt, which reduces the frictional force with the fixing belt; and a pad heat transfer plate provided between the sliding sheet and the fixing pad, which adjusts the heat transfer in a longitudinal direction of the fixing belt. The fixing pad has protrusions and that make contact with the pad heat transfer plate, and forms a gap between the fixing pad and the pad heat transfer plate in a location where the protrusions and are not making contact.