A fixation unit that fixes toner onto a recording paper includes a thermal fixation
roller, a heating part that heats the thermal fixation roller, a compressing part
that presses the thermal fixation roller, and a drive gear, mounted on the thermal
fixation roller, which rotationally drives the thermal fixation roller, wherein
an outer diameter of the thermal fixation roller is equal to or larger than an
inner diameter of the drive gear, as the heating part heats the thermal fixation roller.