An electron beam irradiation device includes an electron gun, a housing, and an electron beam emission window. A rod portion of the housing includes a first tubular member, a second tubular member, a cooling gas flow space, and a wall member. The window is provided at an end portion on a distal end side of the first tubular member. The second tubular member surrounds the first tubular member. The cooling gas flow space includes at least a cooling gas flow path provided between an outer wall surface of the first tubular member and an inner wall surface of the second tubular member. The wall member is provided so as to perform partition between an electron beam emission space and the cooling gas flow space. The wall member is provided with a cooling gas ejection hole. The hole has a flow path sectional area smaller than a flow path sectional area of the cooling gas flow path.