Abstract: A method for estimating a heat generation distribution in a honeycomb structure includes: a first step of allowing a predetermined minute current to flow between electrode layers A1 and B1 to energize a honeycomb structure, and measuring surface potentials at multiple points; a second step of allowing a predetermined minute current to flow between electrode layers A2 and B2 to energize the honeycomb structure, and measuring surface potentials at multiple points; a third step of quantifying, based on the measured surface potentials at the multiple points, at least one of resistances at the multiple points in the honeycomb structure, resistance ratios for energization paths, voltage sharing ratios, and surface potentials of the electrode layers A1, A2, B1 and B2; and a step of estimating a heat generation distribution in the honeycomb structure based on the values quantified in the third step.