Honeycomb structure

A honeycomb structure comprising:

• a center part including a cylindrical honeycomb structure part and a pair of electrodes provided on a side face of the honeycomb structure part, the honeycomb structure part having a porous partition wall and an outer circumferential wall around the porous partition wall, the porous partition wall defining a plurality of cells extending from one end face to the other end face, the plurality of cells defining fluid passages;
• and
• an outer circumferential part provided around the center part,
• wherein an electric resistivity of the honeycomb structure part is 1-200 Ωcm,
• each electrode in the pair of electrodes is formed in a band shape that extends in an extending direction of the cells of the honeycomb structure part,
• one electrode in the pair of electrodes is located opposite the other electrode in the pair of electrodes over a center of the honeycomb structure part, when viewed in a cross section taken in a direction perpendicular to the extending direction of the cells,
• the outer circumferential part has a porous partition wall and an outer circumferential wall at an outermost circumferential position, the porous partition wall defining a plurality of cells extending from one end face to the other end face, the plurality of cells defining fluid passages, and
• a volumetric heat capacity of the outer circumferential part is smaller than a volumetric heat capacity of the center part.