PURPOSE: To provide a new type flame retardant thin insulating wire which has a flame retardant property and a high level abrasion resistant property.

CONSTITUTION: To 100 pts.wt. of a blend polymer of a straight chain form low density polyethylene with a calboxylic acid denatured polymer, an insulator including 30 to 100 pts.wt. of magnesium hydroxide surface processed by a silane coupling agent is applied to the conductor with the thickness 0.1mm to 0.6mm, and cross-linked. The mean particle diameter of the magnesium hydroxide is set 0.1 to 5μm.