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 . <EOS>