To obtain a thermally reversible and electroconductive olefin-based resin composition capable of forming a uniform crosslinking regardless of shape, thickness, etc., of moldings, consequently providing a uniform electroconductivity, and dissociating the crosslinking at a high temperature to provide thermoplasticity.

This electroconductive olefin-based resin composition comprises (A) a modified olefin-based resin which is a modified olefin-based resin modified with an ethylenic unsaturated carboxylic acid anhydride and has an average number of bonds of carboxylic acid anhydride groups per molecule of ≥1, (B1) a hydroxyl group containing compound containing two or more hydroxyl groups or/and (B2) a hydroxyl group containing polymer having an average number of bonds of hydroxyl groups per molecule of ≥1 and (C) an electroconductive filler, the ratio of the number of hydroxyl groups of the component (B1) or/and (B2) to the number of the carboxylic acid anhydride groups is 0.1-5 and the volume specific resistance of the electroconductive olefin-based resin composition is 10-1 to 109 Ω.cm.