In a laser module comprising a hermetically sealed container having inside a semiconductor laser device whose emission wavelength is 350.about.450 nm, generation of organic volatile gas is suppressed in the container and life of the module is prolonged. In a laser module comprising a hermetically sealed container having inside a semiconductor laser device whose emission wavelength is 350.about.450 nm, optical components whose organic volatile gas generation measured by GC/MS is 10 .mu.g/g or less at 150.degree. C. are positioned in the container. In addition, as an organic adhesive to fix the optical components such as a collimating lens is used an organic adhesive whose organic volatile gas generation measured by GC/MS is 100 .mu.g/g or less at 150.degree. C.