An electric fastener driver having a compact size and simple construction. A driver segment provided with a rack is movably disposed in a housing. A flywheel is driven by a motor. A drive shaft is concentric with and integral with the flywheel. A coil spring is fixed to the drive shaft. A driven rotor is coaxial with the drive shaft and has one end portion serving as a spring seat portion positioned within the coil spring. A pinion is disposed at the driven rotor and is meshedly engaged with the rack. An urging section is disposed within the driven rotor. A ball is movably disposed in a through-hole formed in the driven rotor for urging an end portion of the coil spring by the urging section. A solenoid controls a protruding amount of the ball from the surface of the driven rotor.