PURPOSE: To provide a pneumatic selector where the degree of sorting of noncombustibles and combustibles in waste building materials is improved and the recovery is increased.

CONSTITUTION: Inclined plates 60, 62 are arranged in a closed casing 54 in steps. Air introducing ports 63, 64 are provided on the left wall of the closed casing 54, arranged in the upper and lower sides. And air discharge ports 55, 56 are provided on the right wall part of the closed casing 5. Waste building materials falling from a lower end 62a of the inclined plate 62 are effectively sorted into the rubbish of relatively large specific gravity and the one of small specific gravity by an air current A jetted from the upper air introducing port 63 and further are given pneumatic selecting action of the 2nd stage by an air jet stream B from the lower air introducing port 64.