A fixing device to be installed in an image forming apparatus includes a housing for defining the fixing device. In the housing, a heating member which heats a recording medium onto which a toner image is transferred to fix the image and a pressing member which is brought into press contact with the heating member are provided. In the housing, a first conveyance path and a second conveyance path which has a path different from the first conveyance path is formed. A switching member which switches a destination of the recording medium to the first conveyance path or the second conveyance path is arranged in the housing. As a result, when the image recording medium is sent to a paper reversing device installed in the image forming apparatus, the length of a conveyance path extending to the switching member can be shortened.