PURPOSE: To provide surface treating device which can reduce heat energy consumption.

CONSTITUTION: The surface treating device 1 is provided with a displacement varying means in the discharge part 7 of a surface treating zone 2 and a liquid level detecting means which detects a liquid level in a liquid chemical tank 21 for storing a liquid chemical for the surface treatment, respectively. The device is also provided with a control means which produces the control output meeting the detected liquid level of this detecting means to the displacement varying means. The displacement of the discharge part 7 is automatically changed by this control output in such a manner that the liquid level of a liquid chemical tank 21 attains approximately the prescribed liquid level or a fresh water atomizing and supplying means 4 which atomizes the fresh water and applies the atomized water to the work 15 right after the surface treatment is provided before the washing zone.