An engaging unit engages a housing of a fixing device with a main body of an image forming apparatus in an engaged position, and disengages the housing from the main body in a disengaged position. An operating member operates the engaging unit from the engaged position to the disengaged position or vice versa. A holding recession is formed on at least one corner between a front side and a lateral side of the housing. The operating member and the holding recession form a handling unit with which the housing is supported when the housing is attached to or detached from the main body.