A washing machine having a wobbling device. The wobbling device causes a wobbling action of a washboard without rotating the washboard during a washing mode operation, thus effectively washing the clothes. This wobbling device includes a vertical rotary shaft rotated by a washing shaft, and an inclined rotary shaft arranged above the vertical rotary shaft. A first rotary unit couples the inclined rotary shaft to the vertical rotary shaft, thus rotating the two shafts at the same time. An upper surface of the first rotary unit forms a first sloping surface inclined at an angle of inclination. A second rotary unit rotatably receives the inclined rotary shaft therein, and is provided at its lower surface with a second sloping surface corresponding to the first sloping surface of the first rotary unit. A plurality of pins control the relative positions of the first and second sloping surfaces, thus changing the position of the upper surface of the second rotary unit between a horizontal position and an inclined position. A washboard is arranged outside the second rotary unit, and is changed between a wobbling position and a leveled position in accordance with an operation of the pins.