There are several reasons why this theme is raised: first, the house or building as a place of human activity and other storage of valuables requires a system of protection that is easy to operate and affordable price.The purpose of this study is to make a series of alarm systems that can detect thieves and explain how. After doing the data retrieval test and conducted a brief analysis, the authors can draw the following conclusions: Thermal sensor circuit using phototransistor and temperature. The sensor works by exploiting the moment when the temperature by the movement of the door or window is opened by force by the thief so that the alarm triggers to sound. Series of fire sensors (fire) using LM35 as the sensor. When the LM35 gets a fire around it the alarm will sound with a good response time. As a data processor this input device uses an OR gate, a transistor and a relay to adjust the siren activation and display monitoring. Two-tone sirens are generated by the timer as an astable multivibrator. The overall alarm system works well where the sensors have a fast response time. By looking at the tool testing data for each block of the circuit, the error factor is relatively small