To provide a system adopting a frame phase synchronization method that prevents data from being damaged due to a slip by employing an elastic store with a high capacity.

The elastic store 1 sequentially stores input data 6 consisting of frames by using a reset pulse 13 and outputs the stored data as output data 7 according to timing of a reset pulse 14. A 1/4 frequency division phase generating section 2 applies 1/4 frequency division to a received frame synchronizing signal 8 extracted from the input data 6 and outputs 4 kinds of pulses whose phases are shifted by each frame. A selection section 3 receiving the 4 kinds of pulses outputs any of them as the reset pulse 13 according to a control signal. A 1/4 frequency division phase generating section 5 outputs a reset pulse 14 by applying 1/4 frequency division to a reference frame synchronizing signal 15 that is generated by a receiver corresponding to the received frame synchronizing signal 8. A phase comparison section 4 outputs a control signal to the selection section 3 to allow the selection section 3 to select the reset pulse 13 apart by one frame or over with respect to the reference reset pulse 14.