<p>It is an object of the present invention to improve the long-term durability of a power transmission belt. There is provided a power transmission belt characterized in that it includes a rubber layer that is formed of a cross-linked rubber composition and extends in a belt lengthwise direction, and core wires that is adhered to the rubber layer and embedded therein in the belt lengthwise direction, in which the rubber layer with the core wires embedded therein is formed to have a tensile stress of 1.1 to 1.7 MPa when the rubber layer is stretched in the belt lengthwise direction by 10% at 125°C.
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