Disclosed herein is a washing machine. The washing machine includes a main body having a laundry inlet on a front surface portion of the main body, a tub provided inside the main body for storing washing water, a drum rotatably provided in the tub, a pulsator provided inside the drum and configured to be rotated separately from the drum, and a driving device configured to provide power to the drum and the pulsator, wherein no extra structure is mounted on the inner surface of the drum.