Vehicle door sash structure

A vehicle door including: an upright pillar sash extending in elevating/lowering directions of the window glass along one of front and rear edges of window glass; and an elevating/lowering mechanism that operates elevating/lowering movement of the window glass by a driving force of a drive source. The upright pillar sash includes: a design part on a vehicle exterior side; and a main body on vehicle interior side relative to the design part, the elevating/lowering mechanism includes: a slider secured to the glass; a guide rail that guides the slider to move in the elevating/lowering directions; and a transmission member that transmits the driving force from the drive source to the slider, the main body of the upright pillar sash houses the slider, guide rail, and transmission member, and the guide rail regulates movement of the slider in both vehicle interior/exterior directions, on a vehicle interior surface side of the glass.