Fixing device including fixing members for applying pressure on a conveyed sheet

There are provided two members which respectively have a form of a cylindrical roller or an endless belt and which are put in pressure contact with each other so as to form a nip section for fixation. There is provided a heating source which heats at least one of the two members to fixing temperature. In an end section corresponding to a downstream side of a nip section with respect to a sheet conveyance direction, one member out of the two members is curved in a state of protruding toward the other member. The one member has a surface made of fluorine-based resin, and an arithmetic average roughness of the surface is in a range of 0.1 μm to 1.3 μm.