A screwdriver includes a screw rod including a first end and a second end opposite to the first end. The screwdriver defines a screw slot on an external portion adjacent to the second end. The screwdriver further includes a screwdriver bit fixed to the first end of the screw rod, a resisting portion fixed to the second end of the screw rod, a handle placed over a portion of the screw rod adjacent to the second end. A movable element fixed to an inside wall of the handle and tightly closed to an inside surface of the screw slot, and an elastic element placed over the screw rod between the first end and the handle.