Since fuel cell technology is in the commercialization stage, activation cost is also considered an important issue in addition to the manufacturing cost of fuel cell stack. As fuel cell capacity increases, activation time and required fuel consumption are issues that must be addressed to cut costs. In this context, this study suggests an activation method to reduce time and fuel consumption in polymer electrolyte membrane fuel cell. The effects of the newly suggested method, reverse -flow activation, is compared with the conventional activation method through experiments using single-cell and 5-cell stack. As a result, the suggested method reduced 33% of single-cell activation time and 43% of 5-cell stack activation time. A segmented fuel cell is introduced to inspect the local membrane activation progress in detail. As a result, the activation is accelerated in the reactant inlet region. When the reverse flow activation is applied, it seems that the hydration of a membrane in advance near the reactant inlet region and the catalysts activated in advance near the reactant outlet region contribute to faster activation. As a result, the reverse -flow activation method reduces activation time and following fuel consumption. (c) 2020 Elsevier Ltd. All rights reserved.