Signs of anisotropy of the ultra-high-energy cosmic ray (UHECR) arrival direction have been reported by The Telescope Array and The Pierre Auger Observatory. Then, it is expected that source of UHECRs will be clarified. However, because of the quite low flux of UHECR, it is inevitable to extend observatory to much larger than existing ones. Cosmic Ray Fluorescence Fresnel lens Telescope (CRAFFT) project has been developed a low cost fluorescence detector to realize the huge observatory for UHECR observation. CRAFFT project reduced the cost to 1/10 agains fluorescence detectors now in use, and succeeded to observe UHECR air showers by the prototype of CRAFFT telescope. In this presentation, we report the progress of CRAFFT project such as the result of the test observation and data analysis and discuss the future prospect.
UHECR, fluorescence detector