To provide a plasma generating device and a surface cleaning method using this, which keeps the temperature of an electrode and its periphery at an appropriate temperature where a high-temperature plasma current is always normally generated and at which a burnout caused by generation of overheating of the electrode can be avoided.

In the plasma generating device wherein a plasma current is generated with actuating fluid as a medium by the arc generated between the electrode of a negative electrode and a nozzle of a positive electrode with a actuating fluid room formed inside surrounding the electrode, this is characterized in that a steam generator is installed outside the nozzle and that a steam passage to lead the steam generated by the steam generator into the actuating fluid room is installed inside the nozzle. In addition, by the plasma generator being closely approached onto a surface for cleaning, the plasma current is sprayed onto the surface for cleaning and foreign matters adhered to the surface are removed.