Patent ID: 8536539

Claim:
An ion beam generator comprising: a discharge tank for generating plasma that includes ions; a lead-out electrode, having an annular grid portion provided with openings for leading out the ions generated in the discharge tank, while accelerating the generated ions as an annular ion beam, which is led out of the lead-out electrode; and a deflecting electrode for deflecting the annular ion beam, led out of the lead-out electrode, in an annular center direction, the deflecting electrode comprising a first electrode tube and a second electrode tube, the first electrode tube and the second electrode tube being in a circular truncated cone shape having respective openings in an upper surface portion and a bottom surface portion thereof, a diameter of an opening of the second electrode tube being smaller than a diameter of an opening of the first electrode tube, wherein the ion beam led out from the lead-out electrode enters the deflecting electrode between the first electrode tube and the second electrode tube, and is deflected.