An electric tool having therein an electric motor activated by an ON-operation of a switch lever of the electric tool; and a speed changing device configured to reduce a rotational power of the electric motor and output the same to a spindle, wherein: the speed changing device includes a first stage planetary gear mechanism on an upstream side of a power transmitting path and a second stage planetary gear mechanism on a downstream side thereof and is configured to be switched automatically according to an increase in an external torque applied to the spindle from an initial state, in which an internal gear of the second stage planetary gear mechanism is positioned at a rotation-allowed position where the internal gear of the second stage planetary gear mechanism engages with a carrier of the first stage planetary gear mechanism to output a high-speed low-torque to the spindle, to a state, in which the internal gear of the second stage planetary gear mechanism is disengaged from the carrier of the first stage planetary gear mechanism and is displaced to a rotation-restricted position in which the rotation is restricted to output a low-speed high-torque to the spindle; the electric tool includes a speed change lock mechanism configured to lock the low-speed high-torque output state of the speed changing device; a reset mechanism configured to release the speed change lock mechanism on the basis of an OFF-operation of the switch lever and reset the speed changing device to the initial state; and the electric tool includes a delaying mechanism (D1, D2) configured to shift in terms of time between timing of stopping the electric motor achieved by the OFF operation of the switch lever and timing of releasing the speed change lock mechanism achieved by the reset mechanism, such that, when the OFF-operation of the switch lever is performed after the operation in the low-speed high-torque output is terminated, the speed-change lock mechanism is released after a given period from stopping of the electric motor, whereby the speed changing device is reset to the initial state, characterized in that the speed change lock mechanism includes an engaging ball held in a holding hole of a gear housing accommodating the second stage planet gear mechanism, the engaging ball engaging the internal gear and locking the internal gear to the rotation-restricted position when the internal gear is displaced to the rotation-restricted position, and a lock ring configured to be displaced between a lock position in which the engaging ball is locked in engagement with the internal gear and an unlock position in which the engaging ball is accommodated in a relief recess and moved away from the internal gear, the delay mechanism is configured to shift in terms of time between timing when the engaging ball in the state of being engaged with the internal gear is displaced in the direction intersecting the direction of displacement of the lock ring to displace the lock ring to the unlock position and timing when the engaging ball is accommodated in the relief recess to displace the internal gear to the rotation-allowed position. the speed changing device includes a first stage planetary gear mechanism on an upstream side of a power transmitting path and a second stage planetary gear mechanism on a downstream side thereof and is configured to be switched automatically according to an increase in an external torque applied to the spindle from an initial state, in which an internal gear of the second stage planetary gear mechanism is positioned at a rotation-allowed position where the internal gear of the second stage planetary gear mechanism engages with a carrier of the first stage planetary gear mechanism to output a high-speed low-torque to the spindle, to a state, in which the internal gear of the second stage planetary gear mechanism is disengaged from the carrier of the first stage planetary gear mechanism and is displaced to a rotation-restricted position in which the rotation is restricted to output a low-speed high-torque to the spindle; the electric tool includes a speed change lock mechanism configured to lock the low-speed high-torque output state of the speed changing device; a reset mechanism configured to release the speed change lock mechanism on the basis of an OFF-operation of the switch lever and reset the speed changing device to the initial state; and the electric tool includes a delaying mechanism (D1, D2) configured to shift in terms of time between timing of stopping the electric motor achieved by the OFF operation of the switch lever and timing of releasing the speed change lock mechanism achieved by the reset mechanism, such that, when the OFF-operation of the switch lever is performed after the operation in the low-speed high-torque output is terminated, the speed-change lock mechanism is released after a given period from stopping of the electric motor, whereby the speed changing device is reset to the initial state,