This paper describes a support system for archeologists to read "mokkan". A mokkan is a wooden tablet on which text was written by a brush. Many mokkans used in Nara period (from AD. 710 to 794) are being excavated from Heijyo-kyo, Japan (the ancient court in the Nara period). The support system is for archeologists who read mokkans that have been stained, damaged and degraded under the soil. Such mokkans are hard to read even for expert readers. However, the binarization functions of the system extract ink from the image of the mokkans and the character recognition function outputs candidates even for degraded or partially missing character patterns. We made also a graphical user interface to invoke the above functions, provide experts with suggestions and stimulate their inference. Archeologists in the experiment for evaluation enthusiastically accepted the system.