Provided is an electrical stimulus device including a member to be wound around an arm of a user, multiple electrodes arranged on one surface of the member, and multiple optical distance sensors arranged on the one surface of the member. An electrical stimulus signal output from an electrical stimulus generation circuit is provided to the user from a specific electrode of the multiple electrodes to provide a stimulus to a muscle of the arm at a position facing the specific electrode, and the multiple optical distance sensors detect displacement of muscles of the arm. Some electrodes of the multiple electrodes are substantially rectangular electrodes inclined with respect to a circumferential direction of the arm of the user at a predetermined angle of lower than 90°.