To provide an aperture plate support mechanism which can surely prevent the positional changes of an aperture plate held in an aperture holder and an aperture formed at the aperture plate, and to provide a charged particle beam apparatus having the same.
The aperture board support mechanism 21 includes an aperture holder 21a for holding the aperture board 5 having the aperture 5a formed to pass a charged particle beam 10, and a holder holding means 21b for supporting the aperture holder 21a. A plurality of directions of grooves 36, extended radially at the central axis of the aperture 5a as the center, are formed at one of the surface 30b to be supported of the aperture holder 21a and the support surface 28b of the holder support means 21b. A protrusion 35, engaged with the groove 36, is provided at the other of the surface to be supported or the supporting surface. Moreover, the charged particle beam apparatus includes the aperture board support mechanism 21, constituted as described.
