To provide a toroidal infinite variable-speed machine, by which a long service life can be obtained, even under high torque by improving the durability of an outer ring for a power roller.

The toroidal infinite variable-speed machine is provided with the power roller 6 for transmitting power provided between an input and an output disc 1, 2 and the outer ring 9 for the power roller used to support the power roller 6 by bringing into contact with this power roller 6 via a roller 10, and the above outer ring 9 for the power roller has a groove portion 9a into which the above roller 10 is fitted, on the bearing face opposite to the power roller 6. The outer ring 9 for the power is subjected to finish machine after carbonitriding treatment, a surface carbon density C1 is 0.8-1.4%, a surface nitride density N1 is 0.05-0.4%, in the groove portion of the bearing face, a surface carbon density C2 is 0.9-1.4%, a surface nitride density N2 is 0.05-0.4% at the back face portion after the machining, and C1+N1<C2+N2 and each surface hardness of those groove portion in the bearing face and the back face portion is above Hv 650.