A honeycomb structure comprising: a tubular honeycomb structure body having porous partition walls to define and form a plurality of cells which become through channels for a fluid and extend from one end surface to the other end surface, and an outer peripheral wall positioned in the most outer periphery; and a pair of electrode members disposed on a side surface of the honeycomb structure body, wherein an electrical resistivity of the honeycomb structure body is from 1 to 200 Ωcm, each of the pair of electrode members is formed into a band-like shape extending in an extending direction of the cells of the honeycomb structure body, and in a cross section perpendicular to the cell extending direction, one electrode member in the pair of electrode members is disposed on a side opposite to the other electrode member in the pair of electrode members via a center of the honeycomb structure body, the honeycomb structure having an outer periphery constituted of electrode member regions as regions where the electrode members are disposed, and honeycomb structure body regions as regions where the side surface of the honeycomb structure body is exposed, characterized in that there are formed one or more electrode member slits as slits opened in the electrode member region, there are formed one or more honeycomb structure body slits as slits opened in the honeycomb structure body region, an electrode member slit open frontal area as a portion of the electrode member slit opened in the electrode member region is formed to extend in the cell extending direction, a honeycomb structure body slit open frontal area as a portion of the honeycomb structure body slit opened in the honeycomb structure body region is formed to extend in the cell extending direction, and in the cross section perpendicular to the cell extending direction, a length of at least one of the electrode member slits is longer than that of at least one of the honeycomb structure body slits. a tubular honeycomb structure body having porous partition walls to define and form a plurality of cells which become through channels for a fluid and extend from one end surface to the other end surface, and an outer peripheral wall positioned in the most outer periphery; and a pair of electrode members disposed on a side surface of the honeycomb structure body, wherein an electrical resistivity of the honeycomb structure body is from 1 to 200 Ωcm, each of the pair of electrode members is formed into a band-like shape extending in an extending direction of the cells of the honeycomb structure body, and in a cross section perpendicular to the cell extending direction, one electrode member in the pair of electrode members is disposed on a side opposite to the other electrode member in the pair of electrode members via a center of the honeycomb structure body, the honeycomb structure having an outer periphery constituted of electrode member regions as regions where the electrode members are disposed, and honeycomb structure body regions as regions where the side surface of the honeycomb structure body is exposed, characterized in that there are formed one or more electrode member slits as slits opened in the electrode member region, there are formed one or more honeycomb structure body slits as slits opened in the honeycomb structure body region, an electrode member slit open frontal area as a portion of the electrode member slit opened in the electrode member region is formed to extend in the cell extending direction, a honeycomb structure body slit open frontal area as a portion of the honeycomb structure body slit opened in the honeycomb structure body region is formed to extend in the cell extending direction, and in the cross section perpendicular to the cell extending direction, a length of at least one of the electrode member slits is longer than that of at least one of the honeycomb structure body slits.