To provide a connected-screw driver capable of stably retaining a screw, which has just come off from a screw connecting belt, and constantly tightening the resultant screw in a tightening position. A connected-screw driver having a driver unit provided with a motor, an output shaft, a housing, and a bit mounted to the output shaft, a slider case mounted to the housing to permit the bit to be inserted therethrough, and a slider 7 provided in the slider case to be able to reciprocate therein and having an engagement member 20a adapted to abut against a member being tightened, the slider feeding connected screws as the slider reciprocates, and wherein the slider 7 is provided with a chuck mechanism 18 that is movable in an axial direction of the bit and temporarily retains a screw, which has come off from a screw connecting belt, until the screw abuts against a member being tightened, and a regulating mechanism 19 that regulates and fixes a position of the chuck mechanism 18 in the axial direction of the bit.