There are disclosed an aberration correction method and a charged particle beam system capable of correcting off-axis first order aberrations. The aberration correction method is for use in the charged particle beam system (100) equipped with an aberration corrector (30) which has plural stages of multipole elements (32a, 32b) and a transfer lens system (34) disposed between the multipole elements (32a, 32b). The method includes varying the excitation of the transfer lens system (34) and correcting off-axis first order aberrations.