Abstract: A disk device according to one embodiment includes a magnetic disk, a magnetic head, and a flexible printed circuit board. The flexible printed circuit board is electrically connected to the magnetic head. The flexible printed circuit board includes a first layer, a second layer having conductive property, and a third layer having insulation property. The first layer includes a first surface having insulation property. The second layer overlays the first surface, and includes a first conductor and a second conductor spaced from the first conductor. The third layer covers at least a part of the first surface and at least a part of the second layer. The flexible printed circuit board is provided with a first hole that is located between the first conductor and the second conductor with spacing from the second layer and penetrates the third layer.

Abstract: an information processing method in which an electronic device embedded in footwear or attached to the footwear. The footwear having a communicator configured to communicate with one or more external terminals executes an authentication step of authenticating, whether or not a user wearing the footwear is an authorized user, an acquisition step of acquiring at least a payment request of a reward for the user wearing the footwear from the one or more external terminals via the communicator when the authentication has succeeded, an acceptance step of accepting the acquired payment request in accordance with a prescribed action performed by the user, and a transmission step of transmitting an acceptance result to the one or more external terminals via the communicator.