An electrostatic charged particle beam lens includes an electrode including a flat plate having a first surface having a normal line extending in a direction of an optical axis and a second surface opposite to the first surface, the electrode having a through-hole extending from the first surface to the second surface. A circularity in a first region that is on the first surface side and a circularity in a second region that is on the second surface side are each better than a circularity in a third region that is a region in the electrode disposed between the first surface and the second surface.