To provide an endless belt manufacturing method capable of suppressing slanting in a belt width direction with a simple structure without greatly changing a conventional manufacturing method and an endless belt.

An endless belt manufacturing method manufactures an endless belt by winding core wires 4 including strands on molds 1 and 2 in a spiral manner, covering the core wires 4 with resin materials, and burying the core wires 4 in a belt peripheral direction to be spiral in a belt width direction. As the coe wires 4, an S twist core wire 4S and a Z twist core wire 4Z different from each other in a twisting direction are used, and the S twist core wire 4S and the Z twist core wire 4Z are arranged in parallel to be spirally wound on the molds 1 and 2.