The present invention is a horizontal rotary hook for a sewing machine includes an inner bobbin case holder, an outer rotating hook made of a synthetic resin, a sliding surface formed on the rotating hock so as to be slid relative to the bobbin case holder with rotation of the rotating hook while an outer periphery of the bobbin case holder is placed on the rotating hook, an opening defined in an outer peripheral wall of the rotating hook so that a needle thread passes through the opening, and a beak mounted on an outer peripheral wall of the rotating hook for seizing a loop of the needle thread.