Disclosed is a quadrupole mass spectrometer, which is capable of, during an SIM measurement, maximally reducing a settling time-period necessary for an operation of changing an input voltage to a quadrupole mass filter in a staircase pattern, and preventing unwanted ions from excessively entering a detector during a course of changing between a plurality of mass values. It is proposed that the control electrode is also arranged on the front side of the semiconductor substrate. An annular inflow pattern can be established with a central exit flow.