It is possible to provide a frequency characteristics measuring device which can simplify the configuration for performing a measurement and reduce the undue effort required for the measurement.A spectrum analyzer (10) includes: two sets of measuring units having mixers (110, 210), local oscillators (112, 212), and IF sections (120, 220) for separately measuring frequency characteristics of two input signals; a trigger generation section (310) which generates a trigger signal for specifying a measurement start timing in each of the two sets of measuring units; a sweep control section (300) which simultaneously sends an instruction to the two local oscillators (112, 212) when a trigger signal is inputted and performs a sweep control so that the two local oscillators (112, 212) output local oscillation signals of the same frequency at the same timing.