Electrically heating catalytic converter

An electrically heating catalytic converter, comprising:

• a honeycomb structure having an outer peripheral wall and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells each extending from one end face to other end face to form a flow path;
• a pair of metal electrodes connected to the honeycomb structure to apply voltage to the honeycomb structure;
• and
• a housing provided with an inlet and an outlet for allowing an exhaust gas from an engine to flow therethrough, the housing storing the honeycomb structure therein between the inlet and the outlet,
• wherein the honeycomb structure has a plurality of regions disposed coaxially with each other in a cross section orthogonal to an extending direction of the cells, the plurality of regions having different opening percentages from each other,
• wherein the plurality of regions comprise a central region including an axial center of the honeycomb structure and an outer peripheral region adjacent to the outer peripheral wall,
• wherein the opening percentage of the central region is less than or equal to 0.9 times that of the outer peripheral region, and
• wherein a diameter of the central region is more than or equal to 65% and less than or equal to 135% of that of the inlet of the housing.