A clothes dryer comprising: a cabinet including an entry hole in a front cover of the cabinet; a drum disposed in the cabinet and configured to accommodate laundry; a door disposed on the front cover, and configured to open and close the entry hole; at least a lifter installed in the inside of the drum and configured to lift up the laundry within the drum during rotation of the drum, wherein the drive belt surrounds the circumferential surface of the drum; a motor connected with the drum via a drive belt and configured to rotate the drum; a blow fan configured to circulate air, passing through the drum, in response to driving of the motor; a driving controller configured to apply operation power to the motor to operate or stop the motor, and control a rotation speed of the motor; a current sensing unit configured to measure a current value of the motor; and a controller configured to control the driving controller such that the drum rotates according to an operation pattern, consisting of an acceleration stage in which a rotation speed of the drum is accelerated and a maintaining stage in which the rotation speed of the drum is maintained for a predetermined time period, in order to sense the amount of laundry accommodated in the drum, and that the amount of the laundry is calculated based on current values sensed in the acceleration stage and the maintaining stage, wherein the controller is further configured to perform control to maintain the rotation speed of the drum in a range of 39rpm to 63rpm such that, during the maintaining stage, the laundry is lifted by the lifter during the rotation of the drum and is dropped. a cabinet including an entry hole in a front cover of the cabinet; a drum disposed in the cabinet and configured to accommodate laundry; a door disposed on the front cover, and configured to open and close the entry hole; at least a lifter installed in the inside of the drum and configured to lift up the laundry within the drum during rotation of the drum, wherein the drive belt surrounds the circumferential surface of the drum; a motor connected with the drum via a drive belt and configured to rotate the drum; a blow fan configured to circulate air, passing through the drum, in response to driving of the motor; a driving controller configured to apply operation power to the motor to operate or stop the motor, and control a rotation speed of the motor; a current sensing unit configured to measure a current value of the motor; and a controller configured to control the driving controller such that the drum rotates according to an operation pattern, consisting of an acceleration stage in which a rotation speed of the drum is accelerated and a maintaining stage in which the rotation speed of the drum is maintained for a predetermined time period, in order to sense the amount of laundry accommodated in the drum, and that the amount of the laundry is calculated based on current values sensed in the acceleration stage and the maintaining stage, wherein the controller is further configured to perform control to maintain the rotation speed of the drum in a range of 39rpm to 63rpm such that, during the maintaining stage, the laundry is lifted by the lifter during the rotation of the drum and is dropped.