Provided is a power cable, and more particularly, to an ultra-high-voltage underground or submarine cable. In detail, the present invention relates to a power cable which is capable of effectively preventing a decrease in dielectric strength due to penetration of copper powder from a copper conductor into an insulating layer, thereby increasing the lifespan thereof, is capable of preventing damage to insulating paper, semiconductor paper, etc. even when repeatedly bent and unfolded, thereby maintaining an interlayer structure formed by winding the insulating paper, the semiconductor paper, etc., and is capable of improving bendability, flexibility, installability, workability, etc.