A transmission power controller turns on a power supply to a transmitter at a given time taking a power rise time into account before a start time of transmission processing in the transmitter, and turns off the power supply to the transmitter when the transmission processing is finished. A reception power controller turns on a power supply to a receiver at a given time taking a power rise time into account before a time at which an ACK is assumed to be arrival from a wireless communication device on a receiver side responsive to data transmitted from the transmitter, and turns off the power supply to the receiver when the reception processing of the ACK in the receiver is finished.