Patent ID: 8227776

Claim:
An electron beam irradiating apparatus with monitoring device, comprising: an electron beam irradiation means irradiating materials in an irradiation chamber with an electron beam, the electron beam being generated by accelerating thermal electrons, the thermal electrons being emitted from a plurality of filaments; a photographing means capturing lights emitted by the irradiated materials; a storage means storing states of the electron beam irradiation in advance; and a calculating means processing an image captured by the photographing means to decide the state of electron beam irradiation stored in the storage means, wherein the storage means stores luminance of the images that correspond to the states of electron beam irradiation, and stores at least three states of electron beam irradiation selected from a group consisting of normal, axis deviation, broken filament, and vacuum window deterioration, and the calculating means loads the image captured by the photographing means to compare the loaded image with the luminance of the image stored in the storage means, reads the states of electron beam irradiation related to the luminance of images stored in the storage means, and thereby decides the state of electron beam irradiation.