Abstract: This invention provides a magnetron and its application method. The magnetron has a function of in-situ cleaning and can be used to prevent the pollution problem during the ion etching and cleaning. The target of the magnetron can be rotated around its central axis by controlling the inner magnetic field to form two sputtering race-tracks. The cleaning anode and the gas circuit device are set in the local space; after feeding the inert gas, the main sputtering power supply, connected between the target and the main anode of the coater, is used for the sputtering deposition, and the assistant cleaning power supply, connected between the target and the cleaning anode in the local space, is used for sputtered etching and cleaning the target surfaces. The purpose of continuously in-situ cleaning the whole target surface can be reached in that the magnetron target is continuously rotated and the related azimuth of the two sputtering race-tracks is kept constant.