Seal member of automobile door

A weatherstrip (7) has a hollow shape formed by a base (13) to be inserted between opposed engagement parts (11) and (12) of a retainer (6 )and a seal part (14) to come into contact with a surface of a door glass (5) facing a cabin. A center portion of the base (13) has a substantially V shape in cross section projecting toward the cabin. When the center portion of the base (13) comes in elastic contact with the retainer (6) to be subjected to a counterforce from the retainer 6, both side rims of the weatherstrip (7) are pressed against an automobile body or side rims of the retainer (6) with the base (13) interposed therebetween.