A power tool comprising: a rechargeable battery ; a motor ; drive means for driving the motor; an operation unit that is operated to set an operating speed by an operator; battery status detection means for detecting a battery status, wherein the battery status detection means is configured to output an alert signal when the detected battery status indicates that further discharge from the rechargeable battery should be prohibited; and control means for controlling the drive means, wherein the control means is configured to output a control signal to the drive means instructing to drive the motor when the operation unit is operated, to control a rotational speed of the motor with the control signal based on a setting value of the operating speed, and to halt the output of the control signal to the drive means instructing to halt driving the motor in response to the alert signal, characterized in that the power tool further comprises disabling means for disabling the drive means in response to the alert signal, wherein the disabling means is configured to output a disabling signal to the drive means in response to the alert signal to thereby disable the drive means and halt driving the motor irrespective of whether or not the control signal is outputted to the drive means, and if the control signal is being outputted from the control means during the output of the alert signal from the battery status detection means, the disabling signal is prioritized over the control signal and driving of the motor by the driving means is forcibly made impossible, and wherein when the alert signal is outputted from the battery status detection means, both the control means and the disabling means operate in duplicate to halt driving the motor. a rechargeable battery ; a motor ; drive means for driving the motor; an operation unit that is operated to set an operating speed by an operator; battery status detection means for detecting a battery status, wherein the battery status detection means is configured to output an alert signal when the detected battery status indicates that further discharge from the rechargeable battery should be prohibited; and control means for controlling the drive means, wherein the control means is configured to output a control signal to the drive means instructing to drive the motor when the operation unit is operated, to control a rotational speed of the motor with the control signal based on a setting value of the operating speed, and to halt the output of the control signal to the drive means instructing to halt driving the motor in response to the alert signal, characterized in that the power tool further comprises disabling means for disabling the drive means in response to the alert signal, wherein the disabling means is configured to output a disabling signal to the drive means in response to the alert signal to thereby disable the drive means and halt driving the motor irrespective of whether or not the control signal is outputted to the drive means, and if the control signal is being outputted from the control means during the output of the alert signal from the battery status detection means, the disabling signal is prioritized over the control signal and driving of the motor by the driving means is forcibly made impossible, and wherein when the alert signal is outputted from the battery status detection means, both the control means and the disabling means operate in duplicate to halt driving the motor. <EOS>