According to one embodiment, a multi-electron beam device includes at least: a light-emitting element array; a drive circuit controlling the light-emitting element array in a desired light emission pattern; a photoelectric film emitting electrons due to light emitted by the light-emitting elements; a microchannel plate having microchannels multiplying the electrons, the microchannels being arranged at positions corresponding to the light-emitting elements of the light-emitting element array; and an aperture array having apertures arranged at positions corresponding to the microchannels, the apertures being narrower than output apertures of the microchannels and limiting electron beam sizes emitted from the microchannel plate. At least the photoelectric film, the microchannel plate, and the aperture array are disposed inside a vacuum optical column.