PURPOSE: To remove a binder from a compact without causing any defect by arranging a long-sized cylinder having the inlet and outlet for an atmospheric gas in an atmosphere chamber, placing a compact consisting of a sintering powder and binder in the cylinder and forcedly forming a laminar flow.

CONSTITUTION: A long-sized cylinder (e.g. quartz tube) with one end used as an atmospheric gas inlet and the other end as the outlet and having a uniform section is arranged in an atmosphere chamber in plural stages and banks, and a blower is provided at each cylinder inlet opening. Plural injection-molded compacts consisting of a sintering powder and binder are placed on an alumina sheet and inserted into the respective cylinders. Under such conditions, an atmospheric gas (e.g. gaseous nitrogen) is blown from the inlet to forcedly form a laminar flow and brought into contact with the compact at a specified temp. Consequently, the binder is uniformly, slowly and continuously removed from the surface of the compact, and the compact is not cracked or deformed when debindered.