A sensor tag includes: a tag chip that receives a supply of a driving voltage that is generated from a radio frequency (RF) signal that is received from a reader and that transmits sensor data to the reader according to a request from the reader; at least one sensor that receives a supply of a necessary driving voltage from the tag chip and that measures corresponding sensor data; and a micro controller unit (MCU) that receives a supply of a necessary driving voltage from the tag chip and that transfers sensor data that is measured from the at least one sensor to the tag chip.