An endless metal belt with reduced friction and increased durability comprises a pair of layered ring structures (31) each formed by superposing a plurality of thin metal rings in layers so as to be slidable relative to each other, and a plurality of metal blocks (32) arranged along the length of the pair of layered ring structures (31) and supported on the pair of layered ring structures (31) so as to be slidable relative to the pair of layered ring structures (31), and the inner circumferences of the thin metal rings excluding the innermost thin metal ring (R1) are provided with oil retaining grooves (34), and the inner circumference in sliding contact with saddle surfaces (324) of the metal blocks (32) of the innermost thin metal ring (R1) is a flat, smooth surface (35) not provided with any oil retaining grooves and having a small surface roughness.