Abstract: A bit mounting device is adapted for removably mounting a bit on a tool which has a barrel including a mounting hole adapted for receiving the bit. The bit mounting device includes an engaging member engageable with the bit and a control member mounted on the barrel. The control member is movable between a holding position and a releasing position. The control member in the holding position is operable to fix the engaging member in an engaging position for engagement with the bit. The control member in the releasing position is operable to permit the engaging member to move from the engaging position to a disengaging position for disengagement from the bit. A stopper mechanism is operable to hold the control member in the releasing position when the bit is removed from the barrel.