A wire comprising: a core wire; and an insulation coating that covers an outer periphery of the core wire, wherein the core wire includes a distal end region containing a distal end surface of the core wire, and a body region being the part other than the distal end region, the distal end region includes a first distal end region containing the distal end surface, and a second distal end region located between the first distal end region and the body region, and the insulation coating includes a distal end coating part that covers an outer periphery of the first distal end region in a tube shape, an insulation coating body that covers an outer periphery of the body region in a tube shape, at least one coating joint part that joins the distal end coating part and the insulation coating body together in such a way that at least part of an outer periphery of the second distal end region is exposed, characterized in that the insulation coating also includes a coating extension part that extends from the distal end coating part beyond the distal end surface in a tube shape, said coating extension part being formed by stretching of the insulation coating; and in that a welded part having been crushed in a cross direction crossing a longitudinal direction of the wire and closed by welding is formed in the coating extension part. a core wire; and an insulation coating that covers an outer periphery of the core wire, wherein the core wire includes a distal end region containing a distal end surface of the core wire, and a body region being the part other than the distal end region, the distal end region includes a first distal end region containing the distal end surface, and a second distal end region located between the first distal end region and the body region, and the insulation coating includes a distal end coating part that covers an outer periphery of the first distal end region in a tube shape, an insulation coating body that covers an outer periphery of the body region in a tube shape, at least one coating joint part that joins the distal end coating part and the insulation coating body together in such a way that at least part of an outer periphery of the second distal end region is exposed, characterized in that the insulation coating also includes a coating extension part that extends from the distal end coating part beyond the distal end surface in a tube shape, said coating extension part being formed by stretching of the insulation coating; and in that a welded part having been crushed in a cross direction crossing a longitudinal direction of the wire and closed by welding is formed in the coating extension part. a distal end coating part that covers an outer periphery of the first distal end region in a tube shape, an insulation coating body that covers an outer periphery of the body region in a tube shape, at least one coating joint part that joins the distal end coating part and the insulation coating body together in such a way that at least part of an outer periphery of the second distal end region is exposed, characterized in that the insulation coating also includes a coating extension part that extends from the distal end coating part beyond the distal end surface in a tube shape, said coating extension part being formed by stretching of the insulation coating; and in that a welded part having been crushed in a cross direction crossing a longitudinal direction of the wire and closed by welding is formed in the coating extension part.