The present invention provides an electron beam apparatus for evaluating a sample surface, which has a primary electro-optical system for irradiating a sample with a primary electron beam, a detecting system, and a secondary electro-optical system for directing secondary electron beams emitted from the sample surface by the irradiation of the primary electron beam to the detecting system. The electron beam apparatus comprises a multi-beam generator included in the primary electro-optical system for generating electrons emitted from an electron gun as a plurality of primary electron beams, a scanning deflector included in the primary electro-optical system for simultaneously scanning the plurality of primary electron beams on the sample, an objective lens included commonly in the primary electro-optical system and the secondary electro-optical system for decelerating the plurality of primary electron beams for irradiation to the sample, and for accelerating a plurality of secondary electron beams emitted from points of the sample irradiated with the primary electron beams, a secondary electron beam separator included in the primary electro-optical system and the secondary electro-optical system for deflecting the plurality of secondary electron beams passing through the objective lens from the primary electro-optical system to the secondary electro-optical system, at least one stage of magnification lens included in the secondary electro-optical system for enlarging the plurality of deflected secondary electron beams, and a plurality of detectors included in the detecting system and provided corresponding to the plurality of secondary electron beams from the secondary electro-optical system for detecting the secondary electron beams.