In this paper, Li3PO4 (LPO) thin films were coated onto bare and indium tin oxide (ITO) coated glass substrates by thermionic vacuum arc technique. The structural, surface, and optical properties of the LPO films were investigated. The properties of the deposited films were analyzed using an X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, UV-Vis spectrophotometer, and interferometer tools. The miller indices of the crystalline planes of the ITO coated samples were determined as to be (222), (123), (400), (420), (440), (622), and (444). The (200), (121), (112), (301), and (410) miller indices for the crystalline planes were detected for the LPO layers deposited directly on glass. The grain sizes, the microstrain, the lattice strain values, the dislocation density and the number of crystallite per unit area were estimated for LPO layer. The transparency values of the produced Li3PO4/glass (sample S1) and Li3PO4/ITO/glass (sample S2) structures were relatively high 87 and 90% for bare and ITO coated glass substrate, respectively. The reflection values of the coated samples onto bare and ITO coated glass were approximately as 0.05 and 0.06 at 550 nm, respectively.