An analyzer calibrating system intended to reduce calibration time and a consumption amount of calibration gas in the case of concurrently calibrating a plurality of analyzers and includes: a calibration gas line for concurrently supplying the same calibration gas to a plurality of analyzers; and a control unit adapted to determine whether or not an output value of each of the plurality of analyzers supplied with the same calibration gas is stable. The control unit calibrates the analyzer having the output value determined to be stable and stops the supply of the calibration gas to the analyzer having completed with the calibration.