To immediately secure safety in a shelter after an earthquake and to prevent fire from occurring from an electrical heat-generating appliance in an uninhabited house after evacuation by operating a breaker due to a timer function, when an earthquake sensor operates due to earthquake vibrations and electrical systems in the house is broken.

An earthquake sensor 1 is operated by earthquake vibrations, and its outputs is inputted to a timer 2. Then, a preset timer function starts in the timer 2 and the timer 2 outputs a signal as to when the preset time passes and inputs it to a breaker 3 for operating it, thus breaking an indoor electrical system connected to it. By this, required electrical appliances are made usable after a fixed amount of time in the event that an earthquake occurs and safety for sheltering is secured. Further, fires from electrical appliances in an uninhabited house can be prevented by automatically breaking a power supply after the evacuation.