One aspect according to the present invention includes a switch device for a power tool. The switch device includes a switch lever operable to move between an ON position for activating the power tool and an OFF position for stopping activation of the power tool. An on-lock mechanism can lock the switch lever in the ON position. An off-lock mechanism can lock the switch lever in the OFF position. The operation for making the on-lock mechanism effective and the operation for releasing the off-lock mechanism are performed by operating an operation member in different directions from each other or by operating two separate operation members.