A wireless communication system, comprising: a plurality of sensors each of which belongs to a first device type; a relay apparatus belonging to a second device type, the relay apparatus being capable of wireless communication with the plurality of sensors; and a communication apparatus belonging to a third device type, the communication apparatus being capable of wireless communication with the relay apparatus; each of the plurality of sensors comprising a wireless processing unit, the wireless processing unit being configured to perform a process of generating and transmitting a wireless signal containing data to which identification information corresponding to a device type of a device being a destination is added when wireless transmission is performed, the wireless processing unit being configured to perform a process of passing data obtained by wireless processing to an upper processing unit when wireless reception is performed and identification information corresponding to the first device type is added, characterized by: the wireless processing unit being configured to perform a process of not passing the data obtained by the wireless processing to the upper processing unit when the wireless reception is performed and information corresponding to the second or third device type is added, and the relay apparatus comprising a wireless processing unit configured to provide data contained in a received wireless signal to the upper processing device when the received wireless signal contains identification information corresponding to the second device type. a plurality of sensors each of which belongs to a first device type; a relay apparatus belonging to a second device type, the relay apparatus being capable of wireless communication with the plurality of sensors; and a communication apparatus belonging to a third device type, the communication apparatus being capable of wireless communication with the relay apparatus; each of the plurality of sensors comprising a wireless processing unit, the wireless processing unit being configured to perform a process of generating and transmitting a wireless signal containing data to which identification information corresponding to a device type of a device being a destination is added when wireless transmission is performed, the wireless processing unit being configured to perform a process of passing data obtained by wireless processing to an upper processing unit when wireless reception is performed and identification information corresponding to the first device type is added, characterized by: the wireless processing unit being configured to perform a process of not passing the data obtained by the wireless processing to the upper processing unit when the wireless reception is performed and information corresponding to the second or third device type is added, and the relay apparatus comprising a wireless processing unit configured to provide data contained in a received wireless signal to the upper processing device when the received wireless signal contains identification information corresponding to the second device type. the wireless processing unit being configured to perform a process of not passing the data obtained by the wireless processing to the upper processing unit when the wireless reception is performed and information corresponding to the second or third device type is added, and the relay apparatus comprising a wireless processing unit configured to provide data contained in a received wireless signal to the upper processing device when the received wireless signal contains identification information corresponding to the second device type.