Abstract. In order to search a few potential sites for the National Large Optical Telescope (NLOT) project, we have initiated a site survey programme. Since, most of instruments used for the site survey are custom made, we also started developing our own site characterization instruments. The Automated Extinction Monitor which is a small wide field telescope, will be dedicated to record atmospheric extinction in one or more photometric bands. It will give very accurate statistics of distribution of photometric nights and hours. In addition to this it will provide the measurement of sky brightness. In this poster, we briefly describe overall design of the proposed instrument and also report the status of the progress made so for.