To provide a simple rod member fixing structure for fixing a rod member into a through-hole of a plate member, and to provide a fixing method.

The structure comprises the rod member 13 inserted and fixed into the through-hole 22, and the plate member 21 combined therewith and having the through-hole 22. The through-hole 22 has a plurality of tongue protrusions 25 which are protruded toward the inside of the through-hole 22 and elastically deformed in contact with the outer periphery of the rod member 13 when inserted, to constrain the come-off of the rod member 13 by wedge action and fix the rod member 13 into the through-hole 22. The through-hole 22 having the tongue protrusions 25 functions as a fixture such as a prior-art speed nut 14 and eliminates the need for individual fixtures.