The separator for a molten carbonate fuel cell(MCFC) is mode of stainless steel and known to the suscepibility to corrosion due to environments of high temperature molten carbonte electrolyte. Considering the sensitization of stainless steel in the temperature range of 425~$815^{circ}C$, the separator is expected to be sensitized so that the interganular corrosion (IGC) occurs during the cell operation at about $650^{circ}C$. In this study, EPR(electrochemical potentiokinetic reactivation) technique was examined by relating some elements(mainly C and Cr) to the degree of sensitization of austenitic stainless steels in the molten carbonate salt at $650^{circ}C$and the possible mechanism of intergranular corrosion was analyzed.