In other to save energy, several countries recently made laws related to standby power consumption. To success this exertion, we should consider not only power reduction of consumer electronics itself but also efficient automatic control in networked home environment. In this paper, we present a design approach and implementation result of control mechanism for standby power reduction. Proposed mechanism has the host-agent based structure and uses the IEEE 802.15.4 based ZigBee protocol for communication and security between host and agents. We verified reliability of proposed mechanism and reduction effect of standby power; also, we applied implemented device to scenario which is similar to user living pattern. Experimental results demonstrate that in the proposed mechanism, standby power consumption of Agent which is connected to consumer electronics can be reduced by 203 mW.