A washing machine and associated washing method are provided. The method may include rotating a drum, measuring and storing a vibration level of a cabinet while increasing a rotational speed of the drum, and measuring the vibration level of the cabinet after the rotational speed of the drum reaches a target rotational speed and determining whether or not the vibration level of the cabinet is greater than a set value. The method may then include adjusting the rotational speed of the drum if the vibration level is greater than the set value so as to minimize vibration and resonance in a support surface on which the washing machine is positioned.