A transit time fixation device and a control method of the same is provided which can constantly fix transmission delay time in relation to synchronous frames, and allows a high accuracy sampling synchronization control. The frame 101 from a client 3C1 is input to a transit time fixation device 2 via a port 21P1. A frame type judgment part 25a in a control circuit 25 judges the frame type of the frame 101 transmitted from the client 3C1. A destination judgment part 25b acquires a destination address from the received frame 101 to specify a frame control circuit 24Cn+1 to perform a delay process. The frame 101 judged a synchronous frame is delayed at a specific time by a specific time delay part 26a in the specified frame control circuit 24Cn+1.