To provide a marking device in which a laser ray emitting element, a mounting holder, a focus lens, a lens for the astigmatism and the like are easily assembled and adjusted.

The marking device includes a fixing member in which the laser ray emitting element, an emitting element holder, a male screw on the outer circular surface (or a female screw on the inner circular surface) of the emitting element holder and a first lens for focusing the ray are mounted, a female screw on the inner circular surface (or a male screw on the outer circular surface) of the fixing member, and a second lens for the astigmatism. The male screw (or the female screw) of the emitting element holder and the female screw (or the male screw) of the fixing member are fastened and adjusted so that the ray from the laser ray emitting element is focused on the position of the second lens. A projected support portion (or a recessed receiving portion) or a fitting portion (or a support portion) of a mounting member for the second lens is fitted into a recessed support portion (or a projecting portion) or a support portion (or a fitting portion) formed on the fixing member respectively so as to be able to swing. An adjusting screw that fastens the lens mounting member onto the fixing member is adjusted, and the angle of the second lens for the axis of the ray entered from the first lens to the second lens is adjusted by the adjusting screw.