Abstract: A measurement data synchronization method for synchronizing, through use of a data analysis apparatus, time series outputted from first through fifth measuring instruments, includes a step ST1 for acquiring first through fifth reference data outputted from the first through fifth measuring instruments when a reference signal including a stationary interval and a rising interval is inputted to the measuring instruments simultaneously, steps ST3-ST5 for generating first through fifth filter processed data by applying median filter processing to the first through fifth reference data to extract the median value in a prescribed duration, a step ST6 for calculating first through fifth rising times as timing information of rising from each of the first through fifth filter processed data, and a step ST7 for synchronizing first through fifth measurement data outputted from the measuring instruments on the basis of the first through fifth rising times.