To properly clean in a shorter time by maintaining cleaning water supplied by a heating cleaning device at an appropriate temperature in cleaning a water cooler/heater for supplying heated or cooled water.

This heating cleaning device (2) for cleaning a water cooler/heater (10) which supplies heated or cooled water using heated cleaning water (4) is provided with a heating means (an electric heater 8) for heating the cleaning water to be sent to the water cooler/heater, a temperature detention means (a circulatory temperature sensor 18) for detecting the temperature of the cleaning water, a circulation channel (a cooled water pipe 14, heated water pipe 16) for circulating the cleaning water to the water cooler/heater, a circulation pump (12) for circulating the cleaning water to the channel and a controller (a controlling board 22) for controlling the heating means and/or the circulation pump for controlling the temperature of the cleaning water supplied to the water cooler/heater above a fixed temperature.