A curved escalator comprising a plurality of segment steps having step axles connected to an inner and an outer endless loop of step chains so that the steps circulate along the endless loops, and inner and outer sprocket wheels having different diameters for turning around the step axles along a conical surface in turn-around portions of the loop in engagement with the inner and outer endless chain loops, the bottom surfaces of the teeth being engageable with the step axles of the inner and outer sprocket wheels having sloped surfaces that are parallel to the axis of the step axles in the turn-around portion, and the teeth having the same pitch circle. Since the bottom surfaces of the teeth engaging the step axles have sloped surfaces that are parallel to the axis of the step axles in the turn-around portion, and since the pitch circles of the teeth are the same, the driving force is transmitted to the step axles and the step chain, and the steps are smoothly turned around to provide a better ride.