A charged particle beam lens includes a first electrode including a surface having at least one aperture and a second electrode including a surface having at least one aperture. A support intervenes between the first electrode and the second electrode to electrically insulate the first and second electrodes from each other and to support the first and second electrodes in a predetermined positional relationship. A side surface of the support intervenes between the first electrode and the second electrode and includes a non-flat portion having at least one of a projected portion and a depressed portion, and includes a tapered portion. A taper angle formed by the tapered portion and the surface having the aperture of the second electrode is greater than zero degree and less than ninety degrees.