To provide an insulated electric wire and an insulated cable having a high tracking resistance and a stable insulation performance and a weather resistance over a long period without decreasing a tensile elongation and a tensile strength even if a salt content from sea water near a seashore is deposited on an insulator surface of the insulated electric wire and a sheath surface of the insulated cable.

A resin obtained by formulating a silane coupling agent, a cross-linking agent and a catalyst to a compound obtained by adding a metal hydroxide to a polyolefin type or rubber type base resin, or a resin obtained by formulating a silane coupling agent, a cross-linking agent and a catalyst to a compound obtained by adding a silica obtained by a thermal decomposition method and a metal hydroxide to a polyolefin type or rubber type base resin is extrusion-molded on a conductor 1 as an insulator 2 of an insulated electric wire.