To easily carry out attaching and detaching manipulation of a bit or the like for a driver drill.

The driver drill having a switch lever device 2 which can selectively be switched between a start position and a neutral position to permit or stop a start switch 1 carrying out a start manipulation equipped with its housing 17 is provided with a lock mechanism 10 which locks a spindle 19 interlocked with the switch lever device 2 when it is switched to the neutral position, and unlocks the spindle 19 interlocked with the switch lever device 2 when it is switched to the start position.