The heat treatment apparatus that increases a temperature of a processing object and performs a heat treatment in a constant temperature, the heat treatment apparatus includes: a processing chamber which accommodates the processing object; a heating unit which heats the processing object accommodated in the processing chamber; a memory unit which stores two or more temperature control models that are previously created, a temperature controller which controls a temperature of the heating unit; and an apparatus controller which controls the temperature controller and the memory unit, wherein the apparatus controller selects a temperature control model among the two or more temperature control models according to desired heat treatment conditions, and wherein the temperature controller reads out the selected temperature control model from the memory unit to control the heating unit.