A transmission device which selects all or a part of streams from among input streams and then transmits the selected streams, and includes a measuring section and an output control signal generating section. The measuring section inputs an output timing reference signal and an output reference clock required in outputting a stream, detects a time when the output timing reference signal indicates the start of output, and predicts a period in which an output transmission clock to be generated is to be paused. The output control signal generating unit N-frequency-divides (N is an integer of 2 or more) an output reference clock, generates an output transmission clock, and outputs an output timing signal having a predetermined phase correlation with an output transmission clock.