A handle arm mounting structure 9 for a spinning reel includes a fastening section 25a and a washer member 27. The fixing section has a first non-circular hole 25c configured to engage non-rotatably with a non-circular section of a handle shaft. The washer member has a circular disk-like section 27a and an engaging protrusion 27b and is configured to be mounted in an axial direction of the handle shaft. The circular disk-like section has a second non-circular hole 27c configured to engage with the non-circular section. The engaging protrusion is arranged to protrude toward the first non-circular hole from a periphery of the second non-circular hole. The engaging protrusion has an inside surface 27d configured to engage with the non-circular section and an outside surface 27e having a first tapered surface 27f configured to taper toward a tip end and to engage with the first non-circular hole.
