To save a colored liquid, to reduce the amount of a waste liquid, and to control the film thickness of the colored liquid being applied by coating the whole surface of a lamp bulb with the colored liquid by spraying the liquid with a nozzle.

The colored liquid 4 is sprayed and applied on the whole surface of a transparent glass ball 1a of the lamp bulb 1 to be coated by rotating the lamp bulb 1 having the glass ball 1a at a uniform speed around the central axis 2 of the lamp bulb 1, then spraying the colored liquid 4 accommodated in a liquid chamber 3 toward the glass ball 1a of the lamp bulb 1 with the nozzle 5, and relatively moving the nozzle 5 and the lamp bulb 1 along the direction of the central axis 2 of the lamp bulb 1. Thereby, the colored liquid 4 can be saved, the amount of the waste liquid can be reduced, and the film thickness of the colored liquid 4 being applied can be controlled.