A semiconductor device manufacturing method includes: raising and moving a bonding tool, while paying out a wire, in a direction from a second toward a first bonding point to form in the wire a cut portion bent in a vicinity of the second bonding point; lowering and moving a tip of the bonding tool to the cut portion; lowering the bonding tool vertically to thin the cut portion; raising the bonding tool while paying out the wire; and moving the bonding tool in a direction away from the first and second bonding points and along a wire direction connecting the first and second bonding points and then cutting the wire at the cut portion to form a wire tail. This allows the length of the wire tail to be adjusted easily and efficiently to be constant.