A code division multiplex communications system comprises: receiving means (1,2) for receiving a radio wave and transforming the radio wave to an electric signal; voltage-current converting means (101) for converting the electric signal to a current signal; current delaying means (102, 102 2 ... 102 n ) for sequentially reading the electric signal at a timing of a clock pulse; adding and subtracting means (105) for adding and subtracting output currents of the current delaying means in accordance with a spread code; and reproducing means (107) for reproducing a transmission signal on the basis of an output of the adding and subtracting means.