A sensor system in which it is possible to identify a sufficient number of sensors even in a situation where the data length of a packet is limited, as well as a sensor and a receiving device in the same, are provided. A sensor repeating a measurement period for performing measurement and a transmission period for performing transmission at predetermined cycles, includes: a measurement section (11) that outputs during the measurement period measurement information based on predetermined measurement; and a transmission section (12) that transmits during the transmission period, by using a single packet or a plurality of packets, source identification information for identifying a source of a packet, the measurement information, and sensor-related information for identifying the sensor and/or a measurement target equipment of this sensor.