To inhibit events of check and crease effectively in the head end of a linear bulge.

A manufacturing of sipe blade forms a first linear bulge 26 in a first stage and forms a second linear bulge 42 which intersects the first linear bulge 26 by deforming part of the linear bulge 26 in a following second stage. In the method, formation of the second linear bulge 42 can be divided into two steps, since groove depth of a third concave groove for forming the second linear bulge 42 in a first step is set smaller than groove depth of a finished second concave groove 50 for forming the final bent configuration. Thereby deformation in each step gets smaller and occurrence of distortion etc. can be suppressed.