An aberration corrector comprising: a first multipole, a second multipole, a third multipole and a fourth multipole arranged along an optical axis; a first transfer lens system arranged between the first multipole and the second multipole; a second transfer lens system arranged between the second multipole and the third multipole; and a third transfer lens system arranged between the third multipole and the fourth multipole, each of the first multipole, the second multipole, the third multipole, and the fourth multipole are arranged to generate a three-fold symmetric field; characterized in that a sixth-order three-lobe aberration generated in the first multipole and the second multipole and a sixth-order three-lobe aberration generated in the third multipole and the fourth multipole are arranged to cancel each other out; and a six-fold astigmatism is corrected by: a six-fold astigmatism generated by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole; and a six-fold astigmatism generated by a combination aberration of spherical aberrations respectively created in the first transfer lens system, the second transfer lens system, and the third transfer lens system and aberrations created by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole. a first multipole, a second multipole, a third multipole and a fourth multipole arranged along an optical axis; a first transfer lens system arranged between the first multipole and the second multipole; a second transfer lens system arranged between the second multipole and the third multipole; and a third transfer lens system arranged between the third multipole and the fourth multipole, each of the first multipole, the second multipole, the third multipole, and the fourth multipole are arranged to generate a three-fold symmetric field; characterized in that a sixth-order three-lobe aberration generated in the first multipole and the second multipole and a sixth-order three-lobe aberration generated in the third multipole and the fourth multipole are arranged to cancel each other out; and a six-fold astigmatism is corrected by: a six-fold astigmatism generated by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole; and a six-fold astigmatism generated by a combination aberration of spherical aberrations respectively created in the first transfer lens system, the second transfer lens system, and the third transfer lens system and aberrations created by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole. a six-fold astigmatism generated by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole; and a six-fold astigmatism generated by a combination aberration of spherical aberrations respectively created in the first transfer lens system, the second transfer lens system, and the third transfer lens system and aberrations created by the three-fold symmetric fields respectively generated by the first multipole, the second multipole, the third multipole, and the fourth multipole.