Provided is a work tool that can suppress temperature elevation in a motor or a switching element. The work tool is provided with: a motor; a switching element for switching between an ON state in which energization of the motor is allowed and an OFF state in which energization of the motor is interrupted; a target rotational rate setting means for setting a target rotational rate for the motor; a rotational rate control means for controlling the rotational rate of the motor to be at the target rotational rate by varying the ON duration in the switching cycle of the switching element; and a temperature detection means for detecting the temperature of at least the motor or the switching element. The rotational rate control means can set an upper limit to the ON duration in accordance with the detected temperature detected by the temperature detection means and varies the ON duration in a range at or below the upper limit.