A temperature sensor is provided to measure the temperature of immersion liquid at a position where the immersion liquid is supplied. The reading of this temperature sensor is used to control the magnitude of heat input to the immersion liquid using a heater and/or cooler. A controller is used to calculate the calibration error of the temperature sensor relative to a temperature sensor that is provided upstream. The controller uses readings of the temperature difference between the two temperature sensors at one or more mass flow rates in order to estimate the temperature difference between the two temperature sensors at an infinite mass flow rate. The temperature difference at this infinite mass flow rate is estimated to be the temperature calibration error of the temperature sensor to measure the temperature of immersion liquid at a position where the immersion liquid is supplied relative to the upstream temperature sensor.