PURPOSE: To control the feeding amount and on/off of a mixed gas to each gas burner by inputting preset temperature information and preset burner information along the moving direction of an endless orbit in the upper and lower baking zones and controlling the gas flow calculated based on the measured temperature information.

CONSTITUTION: The upper and lower baking zones 3, 4 are divided into plural blocks 31, 32, 33..., 41, 42, 43... and each block is provided with an a gas burner 311, 312, 321-324, 331-333, 411-414, 421, 422, 431 and 432. Standard temperature and buffer temperature range are set for each block according to the baking condition of a food and inputted into a controlling memory device 5. The working state or using condition of the gas burner of each block is also inputted into the controlling memory device. The working temperatures in the upper and the lower baking zones are detected by temperature detection elements 61-66 and each gas burner is put on or off and, at the same time, the supplying amount of mixed gas is controlled by the mixed gas controlling apparatus 71, 72.