An electron beam apparatus for inspecting a pattern on a sample using multiple electron beams includes a plurality of primary electro-optical systems and a plurality of secondary electro-optical systems associated with the respective primary electro-optical systems. The primary electro-optical systems are for irradiating multiple primary electron beams on a surface of the sample, and each includes an electron gun having an anode and an objective lens. The secondary electro-optical systems are for inducing secondary electrons emitted from a surface of the sample by irradiation of the primary electron beams. Detectors are each for detecting the secondary electrons and generating electric signals corresponding to the detected electrons. The anodes of the electron guns of the primary electro-optical systems comprise an anode substrate in common having multiple holes corresponding to the axes of the respective primary electro-optical systems. The anode substrate has metal coatings around the respective holes.