A processing apparatus includes: a process execution unit that executes a process according to a user instruction; a first communication unit that performs wireless communication with a mobile device moved in a predetermined communication area; a recognition unit that recognizes existence/non-existence of use intention; an authentication processing unit that executes a user authentication process in cases where the first communication unit receives a user ID maintained in the mobile device and the recognition unit recognizes that the user who possesses the user ID attempts to cause the process execution unit to execute the process; and a process execution permission unit that permits the process execution unit to execute the necessary authentication process in a case where the reception user ID is recognized as the user ID possessed by the user who has the authority to cause the process execution unit to execute the necessary authentication process.