A method of processing a substrate includes: a placement step of placing the substrate on an electrostatic chuck set to have a predetermined temperature; a first attraction step of attracting the substrate onto the electrostatic chuck by applying a first direct current (DC) voltage to the electrostatic chuck; a holding step of holding the attraction of the substrate by the electrostatic chuck while applying the first DC voltage to the electrostatic chuck, until a temperature difference between the electrostatic chuck and the substrate becomes 30 degrees C. or less; and a second attraction step of attracting the substrate onto the electrostatic chuck by applying a second DC voltage, which is higher than the first DC voltage, to the electrostatic chuck.