Electron beam irradiating device

Patent Pending PROBLEM TO BE SOLVED: To provide an electron beam irradiating device capable of performing heat treatment such as welding, fusion, annealing in a minute region with a diameter of 100 [mu]m or shorter. ; SOLUTION: The electron beam irradiating device comprises an electron source 1 made of tungsten filament, a focusing lens 2 having a pole piece 3, and an objective lens 6. The diameter of an upper passage hole 31a and lower passage hole 33a of an upper pole piece 31 of the pole piece 3 is set to 4 mm or longer, and the current value of the electron beam is increased.