Intruder or a person who intrudes into a building with criminal intent can be prevented or restricted with the help of intrusion alarm system. The intrusion alarm system provides the information about unauthorized entry or threat through alarms, calls and sending SMS to the building manger, security or owner. Intrusion alarm system is set up with wireless devices like PIR motion sensors, door contacts, glass break sensors, panic button, indoor siren and outdoor siren etc. with main controller which monitors the area and generates alarm as soon as it gets input from any of its sensors. Wireless technology makes the system secure, reliable, user, cost effective and more user friendly.