To obtain a vibrating screen used for a fluidized bed to incinerate waste, to prevent clogging of the screen due to incombustible material, and to assure continuous operation for a long time by forming a sieve mesh comprising circular holes having a specified inner diameter in such a manner that the holes are formed at a specified distance from adjacent holes almost all over the screen.

This vibrating screen 10 to be used to separate incombustible material and sands in a fluidized bed to incinerate a waste material such as city garbage has a sieve mesh 12 comprising circular holes of 3 to 6mm inner diameter formed almost all over the screen. The distance of adjacent holes of the sieve mesh 12 is designed as 3 to 6mm so that each sieve mesh 12 is positioned on the top of a regular triangle. The incombustible material with sands in the fluidized bed is introduced while the vibrating screen is vibrated so as to separate the incombustible material from the sands and to remove only the incombustible material. Thereby, a small incombustible material can smoothly pass through the sieve mesh 12, which prevents clogging of the sieve.