abstract |
An ultraviolet light beam irradiating apparatus 10 of the present invention has a bed 13 for supporting a work T in atmosphere, an ultraviolet light irradiation light source 11 for irradiating the surface of the work T with an ultraviolet light beam having a wavelength of 175 nm or shorter, and an inert gas inflow means 22 for allowing an inert gas, preferably nitrogen, helium or argon, into a space in the atmosphere above the work surface of the work T. According to the present invention, the inert gas is allowed to flow into the above space, whereby the oxygen concentration between the ultraviolet light irradiation light source and the work surface is decreases, so that the absorption of the ultraviolet light beam is decreased. |