An opening/closing apparatus for a vehicle, which has a door-lock mechanism, is provided. An output of a motor unit is transmitted to a drum having a planetary gear mechanism, and the slide door of the vehicle is driven by an open-side cable and a close-side cable wound around the drum. A closer cable of the door-lock mechanism is coupled to a carrier of the planetary gear mechanism, and coupled to a latch of the door-lock mechanism via a coupling link. The coupling link is constituted as a toggle mechanism so as to regulate the rotation of the latch by the traction force of the closer cable until the latch is rotated toward a full latch direction from an unlatch position. When the regulation of the latch by the toggle mechanism is released, the latch is rotationally driven toward the full latch direction due to the rotation of the carrier.