A fixing device includes a heating member that heats an unfixed toner image on a printing medium, a conveyance device that conveys the printing medium launched from the heating member after the heating member heats the unfixed toner image, and a heat temperature detection device that detects heat temperature of the heating member. An excessive temperature rise prevention device is provided to forcibly cut off power distribution to the heating member when the heat temperature reaches an abnormal level. A cooling device is provided to cool the excessive temperature rise prevention device. Further provided is a cooling device use control device that controls the cooling device to cool the excessive temperature rise prevention device when the conveyance device stops a conveyance operation.