Disclosed herein is a surface treatment machine that enables the inhibition or reduction of residual abrasives that remain on a workpiece that has been surface treated. An H steel (a workpiece to be treated) 12 is conveyed by means of a conveying device 20. Blasting devices 24A, 24B are then projected abrasives on to the conveying H steel such that it is surface treated. In the downstream of the blasting devices 24A, 24B along the conveying direction, a blowing port 30A of an air blower 30 is located above a conveying path to blow gas to the upper surface 112A of the H steel 12 such that the abrasives on the H steel 12 are blown off and removed therefrom.