The Telescope Array (TA) is an international experiment studying ultra-high energy cosmic rays.
TA uses fluorescence detection technology to observe cosmic rays, and in order to estimate the flux of cosmic rays with the observation of the fluorescence detector (FD), it is necessary to estimate the condition of FD observation area correctly.
Because the cloud has a great influence on the Field Of View (FOV) of the FD, it is necessary to measure the cloud amount and formation on the FOV.
We realize the cloud monitor in the night sky with ccd camera.
In this report, we will introduce the result of CCD cloud monitor.