To provide the synchronization processing system for a measurement signal where a load of a microprocessor of a processing unit processing the measurement signal is relieved and the operating efficiency of the microprocessor is improved.

The system is provided with cameras 14-17 as pluralities of measurement means, a selector 4 that is a selection means selects an output of each measurement signal from the cameras 14-17, a phase measurement circuit 2 that is a phase difference measurement means, provides an output of a control signal to the selector 4, detects a phase difference of the measurement signal selected in response to an input of a phase difference measurement start signal with respect to a reference signal and provides an output of a detection end signal, and a microprocessor 10 as a data processing means that provides an output of the phase difference measurement start signal to the phase measurement circuit 2, receives the detection end signal from the phase measurement circuit 2 and takes synchronization among the measurement signals based on the phase difference data.