Vehicle door structure and method of manufacturing vehicle door

A sashless vehicle door structure configured to separate an interior of a vehicle on an inner side of the sashless vehicle door structure from an exterior of a vehicle on an outer side of the sashless vehicle door structure, the sashless vehicle door structure comprising:

• a first panel having an outer side configured to face the exterior of the vehicle;
• a second panel made of a fiber reinforced resin and provided on the outer side of the first panel, the second panel forming a closed cross-section structure portion with the first panel at an upper portion of a vehicle door, the closed cross-section structure portion having a length direction that extends in a vehicle longitudinal direction;
• an up-stop member that includes joined portions joined to the second panel, a base portion, and an abutment portion non-rotatably fixed on a first side of the base portion, the abutment portion being positioned on an outer side of the closed cross-section structure portion configured to face the exterior of the vehicle, the abutment portion limiting a range of a door glass by abutting a glass-side member provided at a lower portion of the door glass when the door glass is fully raised, the joined portions being joined in a state of being superposed on an inner side of the second panel configured to face the interior of the vehicle;
• rivets that join the second panel and the joined portions;
• a door outer panel disposed on the outer side of the first panel;
• and
• a communication hole formed in the second panel, the communication hole communicating an interior and an exterior of the closed cross-section structure portion, the base portion of the up-stop member being positioned within a perimeter of the communication hole such that the entirety of the base portion is accommodated by the communication hole.