PURPOSE: To change the beam size with the small voltage and improve the connection accuracy between beams by installing a deflector inside two-stage projecting lenses and over a region longer than the lens interval.

CONSTITUTION: A deflector 15 for changing the beam size is arranged inside two-stage projecting lenses 13, 14, and the length of this deflector 15 in the optical axis direction is set longer than the lens interval. The length of the deflector in the optical axis direction can be lengthened without increasing the lens interval. A beam can be deflected with the small deflecting voltage, thus allowing the high-speed response. The lens interval can be decreased if the deflector 15 is not required to be lengthened, thus the aperture interval can be decreased, and the blur of the beam due to the space charge effect is reduced. The beam edge resolution corresponding to edges of the first aperture and the second aperture is reduced, and the connection accuracy between beams can be improved.