An insulating cable having a conductor and an insulator configured by a plurality of resin layers on the conductor, wherein the plurality of resin layers contain the same kind of fluorine resin, a difference in refractive index between a resin layer having the largest refractive index and a resin layer having the smallest refractive index among the plurality of resin layers is 0.03 or less, a layer thickness of an outermost resin layer of the insulator is 0.03 mm or less, and a deviation (coefficient of variation CV) in thickness of the insulator in a cross-section perpendicular to a longitudinal direction of the cable is 0.035 or less.