RFID chip (214) having various types of data is mounted on liquid syringe (200). Chemical liquid injector (100) obtains the various types of data from RFID chip (214) to perform a predetermined operation in accordance with at least some of the various types of data. For, example, a variable pattern for liquid can be recorded on RFID chip (214) of liquid syringe (200) to allow chemical liquid injector (100) to inject the liquid in accordance with the predetermined variable pattern. Thus, a large amount of data can be easily input to the chemical liquid injector to perform the various operations.