Patent Number: 
Section: claims

1. An EUV radiation source, comprising: a first electrode having a first through hole;  a second electrode having a second through hole;  a movable insulator, having a plurality of third through holes, provided between the first and second electrodes,  wherein actuating gas is introduced in the first, second through holes and one of the plurality of third through holes, and voltage is impressed between the first and second electrodes when the first, second and plural through holes are located on a common axis. 2. The EUV radiation source according to  claim 1 , wherein the insulator is disciform. claim 1 3. The EUV radiation source according to  claim 2 , wherein the insulator is rotated with respect to a point. claim 2 4. The EUV radiation source according to  claim 2 , wherein the plurality of third through holes are concentrically provided. claim 2 5. The EUV radiation source according to  claim 1 , further including an ultraviolet laser to generate pre-plasma. claim 1 6. An EUV radiation source, comprising: a first electrode having a first through hole;  a second electrode having a plurality of second through holes;  a movable insulator having a plurality of third through holes, each of which is connected to one of the plurality of second through holes, wherein the second electrode and the insulator are integrally provided, and  wherein actuating gas is introduced in the first hole, one of the plurality of second through holes and one of the plurality of third through holes connected to the one of the plurality of second through holes, and voltage is impressed between the first and second electrodes when the first through hole, the one of the plurality of second through holes and the one of the plurality of third through holes are located on a common axis. 7. The EUV radiation source according to  claim 6 , wherein the insulator is disciform. claim 6 8. The EUV radiation source according to  claim 6 , wherein the insulator is rotated with respect to a point. claim 6 9. The EUV radiation source according to  claim 6 , wherein the plurality of third through holes are concentrically provided. claim 6 10. The EUV radiation source according to  claim 6 , wherein the first electrode and the insulator form hollow portion therein for passing through coolant. claim 6 11. The EUV radiation source according to  claim 6 , further including an ultraviolet laser to generate pre-plasma. claim 6