To provide a barrel polishing device economical and high in reliability capable of miniaturizing the device itself without working dispersion and in a short period of working time.

This device is furnished with an outer peripheral cylindrical barrel tank 1 in which a plate type polishing article and a specified quantity of media are put, four ultrasonic oscillators 111, 112, 113, etc., are installed at a position rotating by 90° against a ultrasonic oscillator adjacent to a canter of the barrel tank 1 on an outer peripheral part of the barrel tank 1, and the plate type polishing article is polished by rotating the barrel tank 1 in a state of generating an ultrasonic wave in the inside of the barrel tank 1. In this case, the ultrasonic oscillators facing against each other are driven at the same phase, and the phase is reversed against the adjacent ultrasonic oscillator.