A remote controller 10 sets, in step S1, a period of time Tx in which a reception mode is maintained after an instruction is transmitted. A generated instruction is transmitted to a communication module 20 (in step S3). The communication module 20 converts the received instruction into a control signal and transmits the signal to an electronic apparatus 30 (in step S4). After a process is executed in response to an instruction, the electronic apparatus 30 outputs information to be returned to the remote controller 10 to the communication module 20 (in step S5). The communication module 20 transmits information (in step S6). The information is received within the period of time Tx after the instruction is transmitted. Thereafter, the reception mode is cancelled (in step S7). After the reception mode is cancelled, the remote controller 10 returns to a sleep mode and operates with the minimum power.