A power tool including: a motor; a rechargeable battery adapted to supply power to the motor; a voltage measurement unit adapted to detect a battery voltage of the rechargeable battery; a switch (25, SW) that is operable by a user, wherein the switch drives the motor when operated by the user; and a control unit that is adapted to control the power supplied to the motor in response to the operation of the switch (25, SW), the power tool characterized in that: whenever the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to a predetermined value, the control unit is adapted to drive the motor to generate an output that is smaller than that before the voltage decreased and became lower than or equal to the predetermined value, the control unit is adapted to perform PWM control on the output of the motor, characterized in that the control unit is adapted to set a duty ratio of the PWM control to a first limited value that is lower than the duty ratio before the voltage decreased and became lower than or equal to the predetermined value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value, and the control unit is adapted to set the duty ratio to a second limited value that is lower than the first limited value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value again. a motor; a rechargeable battery adapted to supply power to the motor; a voltage measurement unit adapted to detect a battery voltage of the rechargeable battery; a switch (25, SW) that is operable by a user, wherein the switch drives the motor when operated by the user; and a control unit that is adapted to control the power supplied to the motor in response to the operation of the switch (25, SW), the power tool characterized in that: whenever the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to a predetermined value, the control unit is adapted to drive the motor to generate an output that is smaller than that before the voltage decreased and became lower than or equal to the predetermined value, the control unit is adapted to perform PWM control on the output of the motor, characterized in that the control unit is adapted to set a duty ratio of the PWM control to a first limited value that is lower than the duty ratio before the voltage decreased and became lower than or equal to the predetermined value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value, and the control unit is adapted to set the duty ratio to a second limited value that is lower than the first limited value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value again. whenever the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to a predetermined value, the control unit is adapted to drive the motor to generate an output that is smaller than that before the voltage decreased and became lower than or equal to the predetermined value, the control unit is adapted to perform PWM control on the output of the motor, characterized in that the control unit is adapted to set a duty ratio of the PWM control to a first limited value that is lower than the duty ratio before the voltage decreased and became lower than or equal to the predetermined value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value, and the control unit is adapted to set the duty ratio to a second limited value that is lower than the first limited value when the voltage detected by the voltage measurement unit decreases and becomes lower than or equal to the predetermined value again.