Abstract: In an electron beam apparatus having a plurality of electron beam columns arranged in a dense arrangement, a transfer device is inserted to operate the electron beam column so that the function and repair may be enhanced. An outer housing of the electron beam column includes a large diameter portion and a small diameter portion, and thus a gap may be formed near the small diameter portion. The transfer device penetrates the gap of the electron beam column at an outer periphery in a linear shape, and is connected to the electron beam column at a central portion.

Abstract: An auto focus control apparatus is provided to perform an auto focus adjustment using astigmatism without being affected by a pattern on a surface. A light receiving optical system includes an unpolarized beam splitter 420 separating a reflection light from an object into a first reflection light and a second reflection light, a first astigmatism producing means 430 arranged on an optical path of the first reflection light, a second astigmatism producing means 450 arranged on an optical path of the second reflection light, a first light detector 440 receiving a light passing through the first astigmatism producing means, and a second light detector 460 receiving a light passing through the second astigmatism producing means. The light source optical system 310 is arranged such that an image forming point of a focus error detecting light is defocused from an observation plane by a predetermined distance.