A device (1) for determining the dew point of a gas in a process chamber (2) which comprises a temperature control element (3) and a temperature sensor (4) for determining the temperature in the process chamber (2). The temperature sensor is in a thermally conductive functional connection with the temperature control element (3), and the temperature control element (3) is designed to actively heat and cool the temperature sensor (4). The temperature sensor is arranged in direct contact with the temperature control element (3).
