To provide a barrel polishing device capable of fixing a drum pulley on a rotating main spindle by an engaging part while eliminating a clutch part, restraining working dispersion of a plurality of barrels to the utmost and high in reliability with no failure of the device itself.

This barrel polishing device is constituted of a driving part 3, a drum 1 to be rotated and driven around a rotating main spindle 110 as its center at a driving transmission part from the driving part, the drum pulley 111 mounted free to rotate around the rotating main spindle as its center and the barrels 21, 22 installed in a state free to rotate with a constant interval in the neighborhood of an outer periphery of the drum, and an engaging part 112b to be engaged with the drum pulley is provided and rotation against the rotating main spindle of the drum pulley is controlled by the engaging part.