To realize streaming reproduction to start reproduction in a minimum waiting time, in a small-scale configuration only in the terminal side.

When streaming reproduction is performed in a mobile phone, an electric field intensity detection part 2 detects the field intensity, and a throughput detection part 3 detects the present throughput of downloaded data. A CPU 11 estimates the transmission speed of a mobile terminal network on the basis of two parameters of the detected field intensity and throughput and calculates a reproduction start point (reproduction start time) of data downloaded to a buffer memory 5 on the basis of this estimated value. Because of the constitution of calculating the reproduction start point so as to correspond to the transmission speed of downloaded data, streaming reproduction to start reproduction in the minimum waiting time is realized in a small-scale configuration consisting of only a configuration in the mobile phone side.