The transport mechanism of electrolyte vapor to internal reforming catalyst is studied by combining two kinds of experiments : post-test analyses of catalyst and out-of-cell tests measuring the transfer rate of electrolyte vapor in the gas phase. In the post-test analyses K and Li pickups show a different behavior : the K pickup shows a saturated behavior around 1.1 wt % pickup after a short period of time, while the Li pickup shows a steady increase during the life of the pickup. As a transport mechanism electrolyte transfer through the gas phase is concluded to be the most likely path. The quick K pickup compared to Li is explained by the difference of the transfer rate in the gas phase (4.4 x 10(-11) mol of K/cm(2)/s versus 1.7 x 10(-12) mol of Li/cm(2)/s). The concentration of the electrolyte vapor obtained is 1.4 x 10(-6) for K and 1.3 x 10(-8) for Li as a mole fraction in a reducing atmosphere, at 0.1MPa, and at 650 degrees C.