PURPOSE: To provide a heat treatment apparatus wherein the whole face of an object to be treated can be heat-treated with good efficiency at a uniform temperature and a throughput can be enhanced in a manufacturing process.
CONSTITUTION: A soaking member 22 is arranged at least on the surface side and the rear side of an object W, to be treated, which is arranged in a treatment position. The soaking member 22 is heated y radiant heat from a facelike heat-generating source 20, it radiates secondary radiant heat, and the object W to be heated is heated uniformly. Especially, a soaking member 22A on the rear side heats the peripheral edge part of the object W, to be treated, which dissipates much heat, from its rear side. The uniformity inside the face of the treatment temperature of the object W to be treated is improved.