PURPOSE: To improve the durability of a gear mechanism, to decrease the number of one-way clutches and to reduce cost for manufacture by interposing the rotary driving shaft of a driving means, with which an inner tank is revolved around a horizontal axial line or inclined axial line, and a high speed/low speed ratio difference axis gear mechanism between the rotary driving shaft and an orthogonal rotary shaft.

CONSTITUTION: By switching a switching mechanism 80, the revolution of an inner tank 30 at the time of washing operation and drying operation and the high speed revolution of a middle tank 21 and inner tank 30 at the time of dehydration can be executed based on the rotation of one motor 51 for tank drive. Especially, since the power transmission from a rotary driving shaft 58 to a rotary shaft 66 is executed by a high speed/low speed ratio pinion 63 and a hypoid gear 68, it is not necessary to separately interpose a deceleration gear mechanism in the rotary driving shaft 58. Accordingly, the number of parts is decreased and work for production and assembly can be easily executed. Further, the power transmission from the rotary driving shaft 58 to the rotary shaft 66 can be smoothly executed and the gear is suppressed to be worn. Then the durability is improved and noise to be generated from a bevel gear or planet gear mechanism can be reduced.