An electronic device system of the present invention includes a first terminal device having a first wireless communicating section which performs wireless communication and a second terminal device having a second wireless communicating section which performs wireless communication and being configured to enter a sleep mode where an operation of part of circuits of the second wireless communicating section is stopped. The first wireless communicating section of the first terminal device generates and transmits a start notification signal which is not a modulated signal wave for releasing the sleep mode of the second terminal device. The second wireless communicating section of the second terminal device in the first sleep mode receives the start notification signal transmitted from the first wireless communicating section of the first terminal device and releases the sleep mode of the second terminal device depending on the value of the electric power of the start notification signal.