We have developed an improved flapping UAV with a payload sufficient to carry a micro-camera system. In order to increase the payload of the airframe, in addition to changing the structure of the struts that make up the airframe, we reviewed the gravity center moving mechanism and the tail structure, which are the characteristic parts of the flapping UAV that we researched and developed and improved the parts and structure. As a result, we succeeded in reducing the weight by 11% compared to conventional UAV. Also, by changing the material of the gearbox, the lift reached 16.3 gf and the UAV successfully flew with a 13.6 g micro camera on board.