LiH molecule is the simplest metal hydride with extremely large permanent dipole moment. Its energy structure and spectroscopy is not well known, and only quite recently several theoretical and experimental investigations shed a new light on this probably one of the oldest (primordial) molecule. We shall describe results of spectral behaviour of LiH molecules in neutral vapor and low pressure electric discharge in specially designed heat-pipe ovens, with emphasize to several applications. A special emhasize will be given to the spatial and temporal behaviour of the electric discharge in which LiH molecules are mixed with He, H2 and Li.