Abstract: An oscillating trough for shotblasting, which prevents workpieces (W) from being damaged when they are turned over in the trough, is provided. The trough includes a depression (24) defined by two surfaces X.sub.4, X.sub.5 extending from the bottom (21) of the transfer portion upwardly and outwardly thereby making an inner angle of 80.degree.-100.degree. and an arcuate surface S connected to the top of each surface X.sub.4, X.sub.5 of the depression. The surface S is an arc in cross section of a radius of 70-100% of the radius of the largest cylinder inscribable in imaginary planes Y and Z each of a predetermined length in cross section, the plane Y at one end intersecting an upper end of the surface X.sub.4 or X.sub.5 with an external angle of 140.degree.-160.degree., and the plane Z at one end intersecting the plane Y with an inner angle of 120.degree.-140.degree..