A temperature changing method includes changing a pressure of a gas supplied from a gas supply to a gap between the substrate and an electrostatic chuck from a first pressure to a second pressure being lower than the first pressure, changing a voltage applied to the electrostatic chuck from a first voltage to a second voltage being lower than the first voltage, changing a temperature of the electrostatic chuck from a first temperature to a second temperature, electrostatically attracting the substrate by the electrostatic chuck for a time in a state where the gas pressure is the second pressure and the voltage is the second voltage, changing the gas pressure from the second pressure to a third pressure being lower than the first pressure and higher than the second pressure, and changing the voltage from the second voltage to a third voltage being higher than the second voltage.