A recording sheet has an unfixed toner image that is formed thereon, and is conveyed to a fixing device. A surface reforming device of the fixing device performs surface reformation for the surface of the toner on the recording sheet by, for example, plasma irradiation or the like, thereby generating a polar group of a hydrophilic property on the surface of the toner. Next, the recording sheet is conveyed to a laser irradiation portion by a recording sheet conveyance device to be irradiated with a laser, in which the toner is fused to be fixed to the recording sheet. The toner on the recording sheet is subjected to surface reforming treatment, thus having increased affinity (adhesion force) with the recording sheet, so that it is possible to secure favorable fixability without pressing.