PURPOSE: To shorten the demodulation impossible time generated by the moving of a transmitter and the level change of a reception signal such as the start of a transmission and to extend the battery life of a receiver, in a direct conversion receiver.

CONSTITUTION: This receiver is provided with a data demodulation means 11 performing a data demodulation by inputting the signals from a first capacitor 7 and a second capacitor 8 and a level detection means 7 outputting the level of a reception signal. Further, the receiver is provided with a first time constant switch means 9 and a second time constant switch means 10 reducing the time constant of a first DC elimination means 7 and the time constant of a second DC elimination means 8 by prescribed time when the level of the reception signal is changed.