When using a drug container having an identification tag fixed or detachably provided at a predetermined position of the container, the tag having drug data on a kind and a concentration of a drug and both or one of upper and lower limits of a flow rate on a continuous infusion and the upper and lower limits, time and flow rate on a one-shot administration recorded thereon, it is possible to ensure safety by prompting for a stop of injection by a warning when a setting beyond the upper and lower limits is performed and rewrite a liquid infusing time and a flow rate and so on required to be set according to symptoms of a patient.