This digital transmission system is provided with a transmitting apparatus that transmits digital data signals and a receiving apparatus that receives the digital data signals transmitted over a transmission path, compares the signals with a predetermined threshold value, and performs decision reproduction. The receiving apparatus is formed by: decision circuits that receive the input of reception signals, discriminate between the respective reception signals using a plurality of threshold values, and output decision results; and a selection circuit that, based on the decision results output from the decision circuit, selects one decision result from one threshold value from among the decision results from each of the plurality of threshold values, and outputs the selected decision result. As a result, the receiving apparatus is able to individually select which decision result to use from which threshold value.