A temperature adjustment method is provided to improve operating efficiency and reduce costs. Control of a heating unit in a thermal processing system including a heating control section is performed based on a first output control pattern obtained by subjecting a detection temperature provided by a first temperature detecting unit to an integral operation, a differential operation, and a proportional operation under a condition of a first set of temperature-setting conditions, a second output control pattern obtained by determining a first heat quantity in a period from the start of an increase in temperature detected by a second temperature detecting unit until the temperature inside the processing chamber reaches a maximum temperature, and using a second heat quantity obtained by subtracting the part of the output provided by the proportional operation from the first heat quantity.