A honeycomb structure body is comprised of a honeycomb body, a pair of electrodes, a pair of electrode terminals and one or more slit sections. The honeycomb body is comprised of a cell formation section and an outer skin section. The outer skin section has a cylindrical shape and covers the cell formation section. The electrodes are formed on an outer peripheral surface of the outer skin section so that the electrodes face with to each other in a radial direction of the honeycomb structure body. Each electrode terminal is formed in an electrode terminal formation section on the corresponding electrode. One or more the slit sections are formed in at least one of an electrode terminal formation section and a circumferential outside section of the electrode terminal formation section.