Temperature control method and substrate processing apparatus

A substrate processing apparatus comprising:

• a processing container configured to accommodate a substrate;
• a heater configured to heat an inside of the processing container;
• and
• a controller,
• wherein the controller controls a process including:
• (a) setting an amount of temperature change with respect to a target temperature having a value up to a second digit smaller than a first digit indicating a control limit value of the heater;
• (b) dividing the amount of temperature change into a first temperature equal to or greater than the first digit and a second temperature less than the first digit, and calculating a ratio of dividing a time segmented by a digit difference between the first digit and the second digit, into a first time corresponding to the second temperature and a second time other than the first time;
• and
• (c) controlling the heater to raise or lower a temperature in times before and after dividing a processing time in a processing step at the ratio.