A capacitive sensor unit of a door handle device is universally adaptable to door handles of various different designs. The vehicle door handle device, having an electrostatic capacitance detection circuit incorporated in a grip portion thereof, includes a sensor unit having a detection circuit insert molded in a plastic member, a hollow cavity formed in the grip portion to receive the sensor unit, and a retaining member made of plastic material for retaining the sensor unit in the cavity. By suitably changing the shape of the retaining member, the sensor unit can be adapted to door handles of different designs.