This project is on Design and construction of a High sensitive fire alarm detector. Fire alarm plays an important role in maintaining and monitoring the safety of the environment. However, the usability of many existing fire alarm systems is well known but could be produced at high costs. Subsequently, it is not affordable for low-income users. This project has three main systems (1) The detector system (2) Monitoring system (3) The appliance system. The detecting system operates as a fire detector. This paper discusses the design and implementation of a fire alarm system. Any signal frequency from the detector at any level is monitored using a monitoring system. The appliance system stops the fire while the entire system is controlled by the microcontroller. The microcontroller is programmed by using C–Programming. The system can sense smoke, light, heat, flames, etc. when the sensor from each level is triggered individually, the main buzzer operates and disconnect the A.C power supply and then shows in the control panel LCD display the area affected and which is not affected. Then it runs the emergency exit motor to escape and water pump to the affected zone to stop the fire.