To reduce power consumption related to a communication of a media converter.

The media converter 12 connects a network 16 including a DVD device 13 and a DV camera 14, and at the same time, it connects an analog monitor 15. The media converter 12 stores a lowering reference ratio and a raising reference ratio to a communication speed of the network 16, and it compares the detected utilization ratio with each reference ratio by detecting the utilization ratio of the network 16. The media converter 12 determines to lower the communication speed of the network 16 when the utilization ratio is below the lowering reference ratio. The media converter 12 determines to raise the communication speed of the network 16 when the utilization ratio is above the raising reference ratio.