Disclosed is a magnetic annealing apparatus including a processing container that performs a magnetic annealing processing on a plurality of substrates accommodated therein in a magnetic field; a substrate holder that holds the plurality of substrates substantially horizontally in the processing container; a division heater including a plurality of sub-division heaters and covering a substantially entire circumferential surface of an outer periphery of a predetermined region of the processing container along a longitudinal direction; a magnet installed to cover an outside of the division heater; and a controller configured to feedback-control a temperature of a predetermined control target heater among the plurality of sub-division heaters, and to control temperatures of the plurality of sub-division heaters other than the predetermined control target heater based on a control output obtained by multiplying a control output of the predetermined control target heater and a predetermined ratio.