In contrast to the wide adoption of unmanned aerial vehicles (UAVs) in the military sector, a far less number of successful applications have been reported on civilian side due to high cost, complexities in operation, and conflicts with existing infrastructure, notably the access of civilian airspace. However, there exist a few cases where UAVs have been successfully adopted to delegate dull, dirty, dangerous tasks in civilian sectors. In this paper, we consider one of such cases, the agricultural application of UAVs and present our work to develop an industrial UAV platform. The developed system is capable of fully autonomous flights with a payload of 30 kg for more than an hour. We present the overview of our program as well as detailed description of the development processes. We believe, when combined with highly reliable hardware and adequate adaptation to the civilian demands, in a not too distant future more UAVs will successfully serve the needs of public.