PROBLEM TO BE SOLVED: To improve sealing performance of a heating container with less contamination of a wafer. SOLUTION: A heat treatment apparatus is provided with a heating container 100 of a hermetically sealed structure consisting of a cylindrical side wall 110, an upper wall 120 and a bottom wall 130; a substrate holding means 500 for holding a wafer W to be housed in the heating container 100; and a lamp unit 200 for heating the wafer W while transmitting the upper wall 120 of the heating container 100. The apparatus is provided with a cylindrical external rotor 300 provided on the external periphery of the heating container 100 and rotating around a vertical axis of the heating container 100; a cylindrical internal rotor 400 provided on the internal periphery of the heating container 100 and allowing the substrate holding means 500 to rotate concentrically with the external rotor 300; a magnetic coupling means 600 for magnetically coupling the external and internal rotors 300 and 400 via the side wall 110 of the heating container 100, and transmitting the rotary movement of the external rotor 300 to the internal rotor 400 to rotate the substrate holding means 500; and a gas bearing 1000 for supplying a gas to the internal rotor 400, and utilizing the pressure of the gas to allow the internal rotor 400 to flow and be supported. COPYRIGHT: (C)2007,JPO&INPIT