A drum type washing machine including a balancer capable of rapidly reducing vibration of a spin tub. The drum type washing machine includes a spin tub which is rotated by receiving rotational force from a driving motor through a rotating shaft, a rear balancer having an annular shape and being coupled to the spin tub, and a shaft flange provided at a center portion thereof with the rotating shaft and coupled to the spin tub so as to uniformly transfer the rotational force to the spin tub. The rear balancer is supported on a rear surface of a rear cover by the shaft flange. Thus, the balls accommodated in the balancer are prevented from moving out of the balancer, even if the balancer is broken due to long-period use.