There is provided an electromagnetic lens which includes an electromagnetic coil wound to be rotationally symmetrical about an optical axis of an electron beam, and a pole piece covering the electromagnetic coil, in which: a gap is integrally formed in either one of an inner wall formed at an inner circumference side of the pole piece and a lower end wall formed in an end portion at an emission side of the electron beam, or a boundary portion between the two walls; the inner wall is formed to be thinnest at a portion close to the gap and to gradually become thicker as a distance from the gap increases; and the electromagnetic lens is formed such that a width in a radial direction thereof is more increased as being closer to the gap along with the change of the thickness of the inner wall.