Provided is a system for helping an operator determine the target ion, collision energy and other analysis conditions. A chromatogram selected by an operator is displayed in a chromatogram display area of an MRM measurement parameter determination window. When the operator selects a point on this chromatogram, the name of a target compound which is registered in an event linked with a range of time including the selected point in time is displayed on a compound name display area. A plurality of mass spectra collected at that point in time are also displayed in a mass spectra display area in a vertically arranged form, using the same scale on the mass axis and the same scale on the intensity axis, with the scales of their mass axes aligned with each other in the vertical direction. The operator can then check whether the selected peak corresponds to the target compound.