A microwave heat treatment apparatus includes: a processing vessel configured to accommodate a substrate therein; a support member configured to rotatably support the substrate in the processing vessel; a microwave introduction device configured to generate a microwave for processing the substrate and introduce the microwave into the processing vessel; a first cooling gas introduction part installed to face a main surface of the substrate supported by the support member, the main surface being a target to be processed; a second cooling gas introduction part installed in a lateral side of the substrate supported by the support member; and a control unit configured to independently control the introduction of a cooling gas from the first cooling gas introduction part and the introduction of the cooling gas from the second cooling gas introduction part.