Provided are a low-cost ball screw device, a method of manufacturing the ball screw device, and a steering device having the ball screw device. The ball screw device is provided with low-cost deflectors formable by simple machining, easy to handle after being machined, and easy to store and mount to another component. The ball screw device (40) includes a screw shaft (20), a nut (21), rolling elements (24), and deflectors (51, 52). Mounting holes (41, 42) each have a pair of circumferentially facing surfaces that face toward each other in the circumferential direction of the nut (21) and parallel to each other. When a plane passing through the center point (Q) of an opening in one end of a second circulation path (53) in each of the pair of deflectors and the axis of the nut (21) is defined as a reference plane, an intersection line between an imaginary perpendicular plane perpendicular to the axis and the pair of circumferentially facing surfaces has an angle with respect to the reference plane.