A washing machine including an inner tub for receiving clothes, an outer tub accommodating the inner tub, a motor for supplying rotational force to rotate the inner tub, and a hanger unit detachably coupled to an upper end of the outer tub and from which clothes are hung, whereby wrinkles of the clothes hung from the hanger unit are reduced by virtue of vibration generated during rotation of the motor. A method of controlling a washing machine including hanging clothes on a hanger unit coupled to the inner tub, rotating the inner tub at a first lower rotational speed, and rotating the inner tub at a second rotational speed higher than the first lower rotational speed.