An insulated electric cable 10 has a core member 1 formed by stranding a plurality of core wires 4, each of the core wires 4 including a conductor 5 and an insulating layer 6 covering the conductor 5, an inner sheath 7 covering the core member 1, an outer sheath 8 covering the inner sheath 7, and a paper tape 2 disposed between the core member 1 and the inner sheath 7 in a state that it is wrapped around the core member 1, in which the outer sheath 8 is formed by a flame-retardant polyurethane resin, and a cross-sectional area of each of conductors 5 is within 0.18-3.0 mm2.