To detect a motion of a hitting tool more precisely by a sensor, provided is a sensor device including: a base member configured to be mounted on a hitting tool via a fitting structure; a substrate joined to the base member; a sensor disposed on the substrate and configured to detect a motion of the hitting tool delivered via the base member and the substrate; a communication unit configured to transmit a detection result of the motion of the hitting tool to an external device; and an exterior member configured to cover the sensor and the communication unit.