Provided is a shot-blasting apparatus which is capable of efficiently perform dust collection and ventilation of an inside of a projection chamber, even using a dust collector having a small-size and low-cost suction device. The shot-blasting apparatus comprises: a cabinet (10); a plurality of process chambers (13a, 13b) provided inside the cabinet in such a manner that each of the process chambers is capable of housing a workpiece therein and selectively movable between a carry-in-and-out position and a projection position; an air inlet port (19) for introducing external air into each of the process chambers therethrough; and an air outlet port provided at a position opposed to the air inlet port across the process chamber set at the projection position, and linearly communicated with an internal space of the process chamber set at the projection position, wherein, according to suction from the air outlet port, air is caused to flow from the air inlet port into the process chamber set at the projection position, and led to the air outlet port while passing through the process chamber set at the projection position.