A vacuum cleaner comprising: a cleaner body comprising a suction motor for generating a suction force; a suction part arranged to communicate with the cleaner body and receive air and dust; at least one battery (121, 122; 123) arranged to supply power to the suction motor; and a controller arranged to control an operation of the suction motor, wherein the controller is arranged to control an output of the suction motor according to a voltage of the at least one battery (121, 122; 123), wherein the controller comprises: a voltage detection part arranged to detect the voltage of the at least one battery (121, 122; 123); and a current adjustment part arranged to adjust an input current of the suction motor so that the suction motor operates at a first reference output when the voltage of the at least one battery (121, 122; 123) is above a first reference voltage, the current adjustment part is arranged to increase the input current of the suction motor in response to a reduction of the voltage of the at least one battery (121, 122; 123). a suction part arranged to communicate with the cleaner body and receive air and dust; at least one battery (121, 122; 123) arranged to supply power to the suction motor; and a controller arranged to control an operation of the suction motor, wherein the controller is arranged to control an output of the suction motor according to a voltage of the at least one battery (121, 122; 123), wherein the controller comprises: a voltage detection part arranged to detect the voltage of the at least one battery (121, 122; 123); and a current adjustment part arranged to adjust an input current of the suction motor so that the suction motor operates at a first reference output when the voltage of the at least one battery (121, 122; 123) is above a first reference voltage, the current adjustment part is arranged to increase the input current of the suction motor in response to a reduction of the voltage of the at least one battery (121, 122; 123). a controller arranged to control an operation of the suction motor, wherein the controller is arranged to control an output of the suction motor according to a voltage of the at least one battery (121, 122; 123), wherein the controller comprises: a voltage detection part arranged to detect the voltage of the at least one battery (121, 122; 123); and a current adjustment part arranged to adjust an input current of the suction motor so that the suction motor operates at a first reference output when the voltage of the at least one battery (121, 122; 123) is above a first reference voltage, the current adjustment part is arranged to increase the input current of the suction motor in response to a reduction of the voltage of the at least one battery (121, 122; 123). a voltage detection part arranged to detect the voltage of the at least one battery (121, 122; 123); and a current adjustment part arranged to adjust an input current of the suction motor so that the suction motor operates at a first reference output when the voltage of the at least one battery (121, 122; 123) is above a first reference voltage, the current adjustment part is arranged to increase the input current of the suction motor in response to a reduction of the voltage of the at least one battery (121, 122; 123).