An infrared sensor and a method of fabricating the same are provided. The sensor includes a substrate including a reflection layer and a plurality of pad electrodes, an interdigitated sensing electrode connected to the pad electrode and formed to be spaced apart from the reflection layer by a predetermined distance and a sensing layer formed on the sensing electrode and having an opening exposing a portion in which an interdigitated region of the sensing electrode connected to one pad region is separated from the sensing electrode connected to the other pad electrode. Therefore, the sensor has an electrode in a very simple constitution, and a sensing layer divided into rectangular blocks, so that current that non-uniformly flows into the electrode can be removed. Accordingly, the sensor in which current of the sensing layer can be uniformly flown, and noise is lowered can be implemented.