PURPOSE: To forma phosphor film of stable quality while always supplying a constant amount of phosphor by weighing phosphor to be supplied from the nozzle of an accumulator by means of an electron scale while supplying said weighed phosphor to a panel.

CONSTITUTION: Phosphor is supplied from the nozzle 5 of an accumulator 3 to an electron scale 6. When the weighed value of the electron scale 6 reaches the preset value, the electron scale 6 outputs a signal for stopping a driving motor of the accumulator 3 by said signal while stopping supply of the phosphor from the nozzle 5. Subsequently, an air cylinder 9 operates to move the electron scale 6 above a panel 10 followed by operating a high rotor 7 to oscillate the electron scale 6. The phosphor weighed by the electron scale 6 is transferred to the panel 10 and when transfer of the phosphor to the panel 10 is finished, the electron scale 6 restores its former position by an operation opposite to the former. Thereby, a constant amount of the phosphor is always supplied to the panel 10 for forming a phosphor film of stable quality.