PURPOSE: To reduce barrel width as narrow as possible as well as to aim at functional improvements, by installing a projecting strip in specific size capable of forming a barrel bottom, in a central part of the width of a rectilinear barrel connecting a semicircular barrel opposed to an annular barrel being vibrated by single exciting force.

CONSTITUTION: When abrasives in proper quantity are charge inside an annular barrel 3 and a vibro-motor 5 is started while works are charged each proper quantity from a work feed chute 11, abrasives and each work are mixed up and advance in spiral circulation as in arrows 18 and 18a. Successively, they run on from a fixed weir 13 to a flap 15 as shown in an arrow 18b, and works and abrasives are separated from each other by a sorting net 14, therefore each work is taken outside as shown in an arrow 18c, and abrasives are put back inside the barrel again. Hereat, a space Na between inner circumferential walls of a rectilinear barrel 6 is set down to size than 1/3 of a diameter in an inscribed circle of the barrel bottom as well as cross width Nb in time of crossing each other along a circle where the inner circumferential wall of the barrel inscribes a circular bottom is set down to less than 1/6 of a diameter of the inscribed circle. Accordingly, a parallel barrel is made to come nearer and the whole body is made into lightweight, thus soft polishing comes possible to be done.