A manufacturing device manufactures a bearing unit including an inner ring member outwardly fitted onto an end portion of a shaft main body of an inner shaft on one side in an axial direction and fixed by a swaged portion extending from the end portion. The manufacturing device includes: a rotating mechanism including a rotor which holds the other side of the inner shaft in the axial direction from below and rotates the inner shaft about a center axis of the inner shaft while the center axis is aligned with an up-down direction, the rotor being mounted below a processing area of the bearing unit; and a swaging mechanism mounted above the processing area and including a punch which is brought into contact with the swaged portion to plastically deform the swaged portion.