To provide a friction-reduced ship which stably supplies a discharge flow along the surface of a hull, the discharge flow being less affected by buoyancy than a conventional case and containing a large volume of microbubbles, to cover the entire part of the submerged hull surface efficiently with microbubbles.

Microbubble generating pumps 55b and 55c each having a tiny foam generating mechanism are disposed on the skin of the a hull submerged under a bow-side water surface 14 so that a uniform discharge bubble flow D of a wide sheet shape accompanying a large volume of tiny foams is sent from a discharge outlet toward the stern along the hull surface. By this method, the hull surface is covered efficiently with tiny foams, which reduces friction resistance during navigation. When the pump bodies are disposed in a part of the ship closer to the bow, a water intake and a discharge port are made open to outside through the hull skin, and shape of a discharge-side casing is arranged so that the discharge bubble flow proceeds along the hull surface toward the stern.