To provide a method for preparing a wide space for an object to be treated in a heating chamber and a cooling chamber, and precisely controlling cooling treatment by measuring a temperature of the object to be treated in real time.

In a multi-chamber heat treatment apparatus having at least a heating chamber for heat-treating the object to be treated and a cooling chamber for cooling the object which has been heat-treated in the heating chamber, this multi-chamber heat treatment apparatus comprises: a temperature sensor for detecting the temperature of the object in the cooling chamber and outputting a temperature signal that indicates the detected temperature; a cooling control unit which is arranged outside the heating chamber and the cooling chamber, and controls the cooling treatment on the basis of the temperature of the object in the cooling chamber, which is indicated by the temperature signal that has been input by the temperature sensor; and an interconnect line for connecting the temperature sensor to the cooling control unit.