A solid-state optical device includes a solid-state element, a power supplying/retrieving portion on which the solid-state element is mounted, the power supplying/retrieving portion supplying or retrieving electric power to/from the solid-state element, and a glass sealing material that seals the solid-state element. The glass sealing material has a thermal expansion coefficient equivalent to that of the power supplying/retrieving portion. The glass sealing material includes a P.sub.2O.sub.5--Al.sub.2O.sub.3--ZnO-based low-melting glass that includes 55 to 62 wt % of P.sub.2O.sub.5, 5 to 12 wt % of Al.sub.2O.sub.3 and 20 to 40 wt % of ZnO in weight %.