Input device, and input system employing same

An input device comprising:

• a stationary part having a first surface and a second surface located below the first surface;
• an operation input part that is provided above the first surface of the stationary part and is movable with respect to the stationary part;
• a detector configured to detect information regarding operation of the operation input part;
• and
• an attachment part provided in the stationary part so as to project downward from the second surface of the stationary part,
• wherein the attachment part includes:
• a holder attachable to an object;
• and
• a coupler configured to couple to the stationary part,
• a holding force maintaining a state where the holder is attached to the object is smaller than a coupling force between the coupler and the stationary part, and
• when a force is applied to the holder from above, the holding force of the holder allows the holder to be fixed to the object.