A housing unit includes: a first housing that contains a cylindrical image holder; a second housing that contains a fuser unit for fixing an image to a recording medium by a heat roller; a protruding unit that protrudes outwardly from a surface of the first housing, which surface faces a circular surface of the image holder; a heat resistant member that is formed of a material having heat resistance higher than that of the protruding unit, and covers the protruding unit; a metallic supporting unit that supports an end of the heat roller; a connecting unit that is formed on the supporting unit and is shaped to contact and fit the heat resistant member; and a fixing unit that fixes the first housing to the second housing at such a position that the connecting unit is fitted to the heat resistant member.