An insert member which is made of a material which is harder than a material forming a molded portion of a glass run which is mounted on an inner side of a sash is provided relative to a bottom portion of the molded portion. The insert member is provided with an insert body, and a projecting portion which is projects from the insert body toward the sash and is fitted in a hole in the sash so as to be locked in place therein. A part of an entire edge of a distal end portion of the projecting portion, which extends in a longitudinal direction of the molded portion is chamfered. In addition, a surface of the insert body facing the sash and at least a peripheral wall portion of the projecting portion are covered with a covering portion which is made of the material forming the molded portion.