A work tool includes a housing, a spindle, a clamp shaft, a biasing member, an operation member, a motion-converting mechanism and a pushing-down member. The spindle is supported to be rotatable around a driving axis. The clamp shaft is movable in the up-down direction relative to the spindle. The biasing member is configured to bias the clamp shaft upward relative to the spindle so as to apply to the clamp shaft a clamping force for clamping a tool accessory between a head part of the clamp shaft and a lower end portion of the spindle. The motion-converting mechanism is configured to move the pushing-down member in the up-down direction along with turning of the operation member around the driving axis. The pushing-down member is configured to be moved downward so as to push the tool accessory downward when the operation member is turned in a first direction.