1. A wafer inspection system using a charged particle beam, comprising: a charged particle source; an objective lens for irradiating a wafer on which a pattern including a hole pattern is formed with a primary charged particle beam from said charged particle source; a sample stage for holding said wafer; a charged particle generator for positively charging the surface of said wafer placed on said sample stage; a deflector for irradiating a predetermined area in said wafer positively charged with a primary charged particle beam; and a detector for detecting a secondary charged particle from said wafer positively charged, wherein an inspection is conducted on said hole pattern on the basis of a signal from said detector.