A fixing device includes an endless belt member and a rotating body that are arranged to come in pressure contact with each other, the endless belt member and the rotating body having a source of heat generation; a pressing member that is arranged within the endless belt member and comes in pressure contact with the endless belt member to the rotating body; and a lubricant reservoir that is provided in the pressing member and reserves a semisolid or solid state lubricant, wherein a width in a central portion of the lubricant reservoir is wider than that in both ends of the lubricant reservoir, and widths along a length direction of the lubricant reservoir narrows from the central portion toward the both ends.