SHIELDED ELECTRIC WIRE AND WIRE HARNESS

A shielded electric wire includes one metal pipe and one electric wire having a conductor and an insulator. An outer diameter of the conductor at 25° C. is set as a, a coefficient of linear expansion of the conductor is set as α, and a temperature difference between a maximum temperature and 25° C. is set as Δt, an outer diameter a′ of the conductor after thermal expansion is a′=a+α×a×Δt, and when a wall thickness of the insulator at 25° C. is set as b and a coefficient of linear expansion of the insulator is set as α, an insulator wall thickness b′ after thermal expansion is b′=b+α×b×Δt, and an inner diameter c of the one metal pipe is set to satisfy c≥a′+2b′.