To provide a burning furnace which minimizes heat radiation loss, for burning board-like electronic parts such as liquid crystal boards, integrated circuit boards, semiconductor boards and the like.

Inside a furnace 2, four rack frames, 3a, 3b, 3c and 3d with a large number of steps in which works can be put by inserting them in from the front, are housed rotatably, and besides, to the open side of the furnace 2, a shutter door 4 with a rectangular slit 5 whose size is large enough to load/ unload one work is attached, and also the shutter door 4 can be moved intermittently vertically in such a way that its slit 5 can be risen and fallen to a position corresponding to one of the frames 3a to 3d from the lowest to the highest and can be stopped to put in and take out works from one of the required rack frames.