Local charge neutralization using secondary electrons generated by an electron beam (EB) for SEM was devised and examined. Neutralization with a high-energy EB compared with conventional very low-energy EB requires no pulsing scheme for TOF-MS extraction voltage. Direct irradiation of high-energy EB to the insulating particle was not effective for neutralization. It was shown that the use of secondary electrons induced by EB-irradiation not on the particle directly but on a metal substrate vicinity of the particle. Charge neutralization was found to be effective even when the EB spot was distant ( 60 mm). (C) 2008 Elsevier B. V. All rights reserved.