A wireless sensor system includes a sensor tag configured to include a radio frequency tag and a communication device configured to wirelessly communicate with one or more sensor tags. Each of the sensor tags is configured to receive a measurement signal from one or more sensor circuits and stores identification information capable of being distinguished from other sensor tags. The communication device includes a transmission means configured to transmit a command signal to the one or more sensor tags and the command signal includes designation information for designating a sensor target serving as an object. Each of the sensor tags generates measurement data on the basis of the measurement signal if the designation information included in the command signal received from the communication device matches its own stored identification information and starts transmission of a response signal including the generated measurement data when a predetermined response start condition is satisfied.