A wireless checking system of a switch and operation unit that are provided in a vehicle includes: a switch disposed at a predetermined location in the vehicle; an operation unit wirelessly connected with the switch and disposed at a predetermined location in the vehicle to be operated by the switch; and a diagnosis equipment wirelessly connected with each of the switch and the operation unit and configured to wirelessly operate the switch and the operation unit, detect an operation state of the switch and the operation unit, and diagnose a wireless connection state of the switch and the operation unit.