An object of the invention is to provide a mass spectrometer system capable of obtaining a mass spectrum with high resolution as the mass number of an ion becomes higher. In the mass spectrometer system of the invention, a control unit 8 controls a mass spectrometry unit 4 so that a direct current voltage U, an amplitude V of a radio-frequency voltage, and a frequency F of the radio-frequency voltage, which are applied to a quadrupole electrode 13, are increased as a mass-to-charge ratio m/z of an ion of a target for mass spectrometry becomes larger. By controlling in this manner, the ion frequency when the ion passes through the inside of the mass spectrometry unit 4 is increased as the mass number of an ion becomes higher, and therefore, it is possible to obtain the mass spectrum with higher resolution.