To provide a lighting device utilizing microwave, which is provided with a dielectric mirror for reflecting forward light emitted from an electric lamp.

The lighting device utilizing microwave comprises a waveguide 4 for transmitting microwaves generated from a magnetron 1, a mesh screen 6 for allowing light to pass through it while blocking a leakage of the microwaves, the electric lamp 5, which emits light by the microwaves, the dielectric mirror 10 formed in such a way that it allows the microwaves to pass through it but reflects forward the light emitted from the electric lamp 5 in parallel, and a reflective mirror 7 for reflecting forward the light emitted from the electric lamp 5.