Patent Number: 
Section: claims

1. An electrostatic lens array comprising:multiple substrates spaced from each other by intervals, each of the multiple substrates having an aperture for passing therethrough a charged particle beam,wherein with respect to a travelling direction of the charged particle beam, a peripheral contour line formed by any one of surfaces of the multiple substrates other than an upper surface of a most upstream substrate and a lower surface of a most downstream substrate has a protruding portion protruding from a peripheral contour line of both of the upper surface of the most upstream substrate and the lower surface of the most downstream substrate,wherein a position of the protruding portion is defined by a position regulating member, whereby parallelism is adjustable so that a surface including the protruding portion is parallel to a surface to be irradiated with the charged particle beam after passing through the aperture, andwherein the position regulating member is in contact with the protruding portion. 2. The electrostatic lens array according to claim 1, further comprising a support portion configured to support the protruding portion, wherein the parallelism is adjustable by the position regulating member via the support portion. 3. The electrostatic lens array according to claim 1, wherein the position regulating member comprises any one of a laser measuring machine, a capacitive sensor, an abutting jig, and a combination thereof. 4. The electrostatic lens array according to claim 1, wherein the multiple substrates comprise three electrodes in which a negative voltage is applied to an intermediate electrode, and other electrodes are connected to a ground. 5. A charged particle optical system comprising:a collimator lens configured to collimate a charged particle beam emitted from a charged particle source;an aperture array configured to divide the collimated charged particle beam; andan electrostatic lens array configured to focus each of the divided charged particle beams so as to irradiate a sample surface,wherein the electrostatic lens array includes multiple substrates spaced from each other by intervals, each of the multiple substrates having an aperture for passing therethrough the charged particle beam,wherein with respect to a travelling direction of the charged particle beam, a peripheral contour line formed by any one of surfaces of the multiple substrates other than an upper surface of a most upstream substrate and a lower surface of a most downstream substrate has a protruding portion protruding from a peripheral contour line of both of the upper surface of the most upstream substrate and the lower surface of the most downstream substrate;wherein a position of the protruding portion is defined by a position regulating member, whereby parallelism is adjustable so that a surface including the protruding portion is parallel to a surface to be irradiated with the charged particle beam after passing through the aperture, andwherein the position regulating member is in contact with the protruding portion. 6. The charged particle optical system according to claim 5, further comprising a blanker array configured to deflect each of the divided charged particle beams in accordance with a drawing pattern. 7. An electrostatic lens array comprising:multiple substrates including at least first and second substrates; anda spacer contacting a lower surface of the first substrate and an upper surface of the second substrate to space to the first and second substrates from each other, each of the multiple substrates having an aperture for passing therethrough a charged particle beam,wherein with respect to a travelling direction of the charged particle beam, the spacer has a protruding portion protruding from a peripheral contour line of one of the upper surface of the most upstream substrate and the lower surface of the most downstream substrate,wherein a position of the protruding portion is defined by a position regulating member, whereby parallelism is adjustable so that a surface including the protruding portion is parallel to a surface to be irradiated with the charged particle beam after passing through the aperture, andwherein the position regulating member is in contact with the protruding portion.