According to an aspect of the invention, a fixing device includes a laser beam irradiation unit and a conveying unit. The laser beam irradiation unit includes a plurality of laser beam sources and emits a plurality of laser beams to a surface of a recording medium. The conveying unit conveys the recording medium and/or the laser beam irradiation unit so that irradiated regions irradiated with the laser beams are moved in a given direction. When the plurality of laser beams is emitted to a toner image to fix the toner image, the plurality of laser beams satisfies conditions (A) and (B). The condition (A) is that the plurality of laser beams has substantially the same beam power and substantially the same width. The condition (B) is that the plurality of laser beams is independently emitted to the toner image.