There is a tendency of the intensity and the shape of a spectrum to be measured transitioning with the passage of measured time, depending on the volatility and the reactivity of a component. A mass spectrometric system includes: a mass spectrometric unit that measures a specimen and outputs a mass spectrum; and an estimator that has an estimation rule on content information, the estimation rule being assigned to each component and each measurement time. The estimator estimates, based on a mass spectrum output from the mass spectrometric unit, content information on each component of a plurality of components that may be contained in the specimen in accordance with the estimation rule.