<b>Analog CMOS Image Sensor based Radon Counter</b> Radon is an invisible, odorless, and chemically inactive radioactive gas produced by the decay of uranium ore. Various types of equipment and components have been proposed for use in effective radon detection. In this paper, we describe a radon detector that uses an analog CMOS image sensor module. Based on our studies, we believe that this system would be helpful in protecting many people from the dangers associated with radon exposure. radon, radon detection, CMOS image sensor module, radon exposure 54-59 Issue-2 Volume-2 Chungyong Kim | Gyu-Sik Kim