A power tool includes a housing (10), a spindle (4) supported in the housing to be pivotable or rotatable about a driving axis, a clamping shaft (60) that is selectively movable in the up-down direction relative to the spindle, a biasing member (70), a release member (71) and an actuating member (50). The release member is selectively movable in the up-down direction relative to the spindle and is configured to selectively interrupt transmission of upward biasing force from the biasing member to the clamping shaft. The release member is also configured to be locked to the spindle in a locked position while transmission of the biasing force is being interrupted. The actuating member is movable upward in the up-down direction relative to the spindle in response to being pressed upward by a clamping part (64) or by a tool accessory (91) to thereby unlock the release member from the spindle.