A response factor that is a signal strength ratio with respect to a reference compound for various compounds is previously stored in a response factor storage (22). When an operator instructs to estimate an analysis limit value, a measurement unit (1) performs GC-MS analysis on a sample containing the reference compound a plurality of times under control of an analysis controller (3). A signal strength calculator (23) obtains a signal strength value of the reference compound based on an analysis result of the measurement unit (1), a relative strength calculator (24) calculates a relative standard deviation from the plurality of measured signal strength values, and calculates the relative standard deviation of a target compound from the response factor of the target compound read from the response factor storage (22). An analysis limit value estimator (25) estimates a limit of detection (LOD) and the like from the relative standard deviation of the target compound by a known method, and displays the LOD on a display (6). Consequently, the analysis limit value can simply be obtained without actually measuring the target compound.