Provided is a wound body formed by winding a long sheet. The wound body is supportable by a support shaft. The support shaft includes a cylindrical outer peripheral part that includes a first projection located at a proximal end and a second projection located at a distal end, and includes an inner peripheral part that includes a first recess part located at the one end and recessing outward in the radial direction and a second recess part located to extend from the one end to the other end and recessing outward in the radial direction. A recessing amount of the second recess part is smaller than that of the first recess part. The support shaft and the core body are integrally rotatable around the central axis by engagement of the first projection with the first recess part in a state where the core body is mounted on the outer periphery of the support shaft. The circumferential position of the first projection around the central axis is aligned with the circumferential position of the first recess part around the central axis by engagement of the second projection with the second recess part when the core body is mounted on the outer periphery of the support shaft.