PURPOSE: To make possible to take recovered swarf out of a cabinet at high speed, by providing a shot blasting apparatus with a shot selecting structure that can readily remove the swarf deposited in selecting plates.

CONSTITUTION: To mount the selecting plates 16, 17 into the cabinet, first the selecting plate 22 is inserted along support rails 14, 15 from an opening 2b into the cabinet until only anchoring pins 23 and anchoring flanges 24 project from the opening 2b. Then, notches 16f formed in a rear plate 16e of the selecting plate 16 are engaged with the anchoring pins 23 from below, and the rear plate 16e of the selecting plate 16 is joined to a front plate 16c of the selecting plate 22. Then the selecting plate 16 is pushed into the cabinet until the front plate 16c abuts on a plate 2c to complete the mounting of the selecting plates 16, 22. To clear the swarf, the selecting plates 16, 22 are withdrawn by the reverse procedure and the swarf is discarded.