JRC has been developing SAW sensor devices as a SAW application to non-communication field during the past few years. SAW liquid sensor, a sort of the developments, is an electronic device that can detect wide variety of physical quantity of liquids by use of surface acoustic wave properties. SAW liquid sensor is one of the most promising devices in the wide range of sensing applications by reason of its excellent productivity. As an application of SAW liquid sensor, JRC has developed a SAW methanol concentration sensor for DMFC, which is an attractive device as mobile power sources. Although the developed sensor has simplified structures, the sensor shows equal measurement performances with its competitive devices. Also, excellent responses of the developed sensor to characteristics change of specimen liquids, which was unknown before that, have been discovered during the evaluations. This report describes general descriptions of SAW methanol concentration sensor and evaluation results.