Powder including at least a superconducting phase is degassed (step S1). After the powder is filled in a silver pipe (step S2), the silver pipe is degassed at a high temperature (step S3). After a plurality of single-core wires are inserted into another silver pipe to attain a multi-core structure, the silver pipe is degassed at a high temperature (step S5). The silver pipe is sealed under a reduced pressure (step S6). Therefore, even when a multi-core superconducting wire is manufactured, a manufacturing method of a superconducting wire capable of preventing swelling of the wire caused by a residual gaseous component can be obtained.