This study presents a sensitivity map that describes the effects of the microstructural parameters on the current generation in thin active reaction layers of solid oxide fuel cells (SOFCs). The electrode processes in the active reaction layers (composed of ionic and electronic particles) are simplified to an electrochemical reaction/charge transport problem, assuming that the symmetric Butler Volmer reaction kinetics is valid. This problem is numerically solved to determine the sensitivity exponents for the volume-specific three-phase boundary length (TPBL), effective ionic conductivity, and active reaction layer thickness for various operating and overpotential conditions. The sensitivity map presented in this study is expected to be a useful guideline for analyzing and predicting the performance variation caused by microstructural changes and designing and optimizing the electrodes of SOFCs. (C) 2016 Elsevier Ltd. All rights reserved.