To eliminate a binder drip failure occurring during heat-treatment of a laminated ceramic member.

In this heat treating furnace continuously heat-treating an object to be burnt containing a binder component, the furnace being at least in a temperature range for volatilizing the binder, an air supply pipe 2 and an air exhaust pipe 3 are placed in front and in the rear, and extended in the width direction to cross the inside of the furnace at the height above the object to be burnt to avoid hindering the movement of the object. Furnace gas is supplied from a plurality of gas holes 2a (unshown in the figure) drilled in the air supply pipe 2 and sucked into a plurality of gas holes 3a piercingly formed in the air exhaust pipe 3, thereby forming a one-way gas flow from the air supply pipe 2 to the exhaust pipe 3 in a space above the object in the counter direction to the moving direction of the object.