There is provided a bottle cap opener comprising: a cylindrical body including an upper cylindrical body and a lower cylindrical body; an elongate screw bar passing through the upper cylindrical body at a center thereof, and passing beyond the upper cylindrical body upwards; a handle coupled to the elongate screw bar at a top end thereof; a screw protrusion coupled to the elongate screw bar at a bottom end thereof; both wings pivotally coupled to the upper cylindrical body at both-side pivotal portions thereof via both-side pivotal shafts respectively; and a silicon-based cap gripper formed on an inner face of the lower cylindrical body so as to grip a bottle cap tightly therein.