An embedded type lighting device is formed by assembling a light body to the light body mounting base which is to be mounted to a fitting face. The light body provides the lamp structure made of a plastic material, the lamp socket, and the connector for electrical connection and mechanical connection to the light body mounting base. The light body mounting base includes a base structure made of a plastic material, a terminal block, and connection means for receiving, electrically connecting and mechanically supporting the connector of the light body. The light body is connected both electrically and mechanically to the light body mounting base by the connector. Yet, it is possible to omit a special insulation structure with regard to the terminal and the connection means by making the light body structure and the base structure of a plastic material. Thus the workability of the light body is improved and the construction of both the light body and the light body mounting base is simplified.