ROTARY BODY AND MANUFACTURING METHOD THEREFOR

A rotary body includes a rotary part and a device fixed to the rotary part. The device includes a substrate, a power receiver, and a flat secondary battery attached to the substrate. The power receiver has a structure for receiving power supply using electromagnetic induction. The secondary battery includes an exterior body including a positive electrode can having a bottomed cylindrical shape and a negative electrode can having a bottomed cylindrical shape. The secondary battery is disposed closer to a rotation center of the rotary part than the substrate as viewed from the rotation center of the rotary part.