Abstract: There is provided n information managing/providing system including a plurality of clients (2) and server (3). Each of the clients (2) includes a plurality of sensor units (10) to detect environmental information on a residential house, receiver (11) to receive the housing-environmental information sent from the sensor unit (10) according to a predetermined radio communication standard, housing-environmental information storage unit (12) to store the housing-environmental information, and a transmitter (13) to send the housing-environmental information to the server (3). The server (3) extracts arbitrary information on the basis of the housing-environmental information supplied from the client (2) and provides the extracted information to a pre-registered user via a network.

Abstract: There is provided a power-off system including a connector (10) connected at one end thereof to a system power line (A) and at the other end to an electric appliance (10) and which connects or disconnects a power supplied from the system power line (A) to the electric appliance (100), a sensor (11) to detect environmental information, and a signal transmitter (12) to generate a predetermined signal on the basis of the environmental information detected by the sensor (11) and send the generated predetermined signal to the connector (10). For example, the sensor (11) having detected an earthquake will send an quake signal to the signal transmitter (12), and the latter will open the circuit of the connector (10) to prevent a fire possibly caused by the earthquake.