PURPOSE: To make it possible to form a constant and uniform fluorescent material layer on the inner surface of a bulb, by a method wherein a fluorescent material is sent to an injecting nozzle when coated on the inner surface of the bulb and sent to a fluorescent material receiving container through a powder separating apparatus when coating is not carried out.

CONSTITUTION: Air is sent into an injector 2 provided to a fluorescent material receiving container 1 receiving a fluorescent material 1a from an air send-in device to suck the fluorescent material 1a in the container 1 and said fluorescent material 1a is discharged along with air from a discharge port. An electrostatic powder coating nozzle 5 connected to said discharge port through a powder transfer pipe 4 as well as having a charging apparatus mounted therein injects the fluorescent material to the inner surface of a bulb such as a fluorescent lamp or the like from the leading end thereof. In addition, a three-way change- over valve 6 provided on the way of the transfer pipe 4 communicates the injector 2 and the nozzle 5 for a predetermined time when the bulb 7 is corresponded to the nozzle 5 as well as a powder separating apparatus 8 communicated with one port of the valve 6 separates the fluorescent material and air sent thereinto to send the separated fluorescent material into the container 1.