PURPOSE: To supply steam or hot water where the quality of steam is controlled enough to perform each kind of cleaning without break so that the cleaner can be fit for a long time of use, in dental technical work.

CONSTITUTION: This is a dental steam cleaner of once-through boiler system equipped with a heating block 1, which heats the washing water 5a supplied into a passage 1b by the electric heater 1a is arranged neighboring to the passage 1b, an electromagnetic pump 4, which is disposed in the middle of the water supply pipe 4a leading to the block 1 and the tank 5 reserving the washing water 5b, and a nozzle 3a which is connected to the block 1 and sprays steam or hot water from the head. This is equipped with a control circuit 6 which controls the heat generation by adjusting the flow rate of the washing water 5b supplied to the block 1 by the electromagnetic pump 4, and also, adjusting the current application to the electric heater 1a, based on the temperature of the block 1 detected by one or more temperature sensors 2 arranged at the block 1.