A power tool has a base, a main unit, a cutter, a bolt, an engagement member, and a unit. The base has a sliding surface slidable on a workpiece, another surface opposite to the sliding surface, and an opening in the base. The main unit is movable in a first direction substantially perpendicular to the sliding surface. The cutter is driven by a electric motor in the main unit to protrude through the opening from the sliding surface during an operation. The bolt extends in the first direction on the first side, a first male thread, and one end supported by the base. The bolt is rotatable aboutthe longitudinal axis. The engagement member has a first female thread threadably engaged with the male thread. The engagement member is movable between an engaged position with the boot and a disengaged position therewith. The unit maintains the engagement member at the disengaged position in a second direction. The rotation of the bolt causes the first male thread portion to thread with respectto the first male thread portion, thereby moving the main unit in the first direction and adjusting a distance of the main unit to the sliding surface.