An ultraviolet laser source which can stably emits ultraviolet light having a sufficient output and low coherence, as a light source for an exposure unit, for a long period of time, is compact, and allows easy maintenance. The laser source is constituted by 10.times.10 laser elements, i.e., a total of 100 laser elements. Each laser element includes a laser beam emitting section for emitting light having a long wavelength, i.e., visible or infrared light, and a wavelength converting section for converting the emitted laser beam into ultraviolet light. The laser beam emitting section includes a semiconductor laser, and a solid-state laser. The wavelength converting section contains a nonlinear crystal for converting the wavelength of incident light and outputting the resultant light.