To solve a problem on poor workability in conventional screws and screwdrivers such that a screw driving direction is inclined or a screw groove may be broken, depending on an angle and a level of pressing force to the screwdriver when a blade edge of the specific screwdriver is pressed to a head part of the screw to transmit torque to the screw.

Two or more through holes for the groove are formed on the screw head part receiving the torque of the screwdriver, and the screwdriver is provided with projecting parts simultaneously inserted into the holes at its tip end, thus an upper part of the screw is held by the screwdriver when the tip end part of the screwdriver is inserted into the holes of the head part of the screw, and the screw and the screwdriver can be easily held straight.