PURPOSE: To eneble the time synchronization between computers in an equivalent manner by providing a plurality of computers each with an internal time piece synchronizing the JJY.

CONSTITUTION: The reference radio wave JJY is inputted into a receiver 12 to amplify and demodulate. A pulse generator 13 generates a reference pulse based on received signals of JJY. This reference pulse is transmitted to a clock device 15 through an execlusive circuit 14 to generate time information. A computer 17 takes the time information into a time register 18. The independent adoption of said structure enables a plurality of computers to be synchronized satisfactorily.