A foldable pedal apparatus for a vehicle, turns into a pop-up state in which a pedal pad protrudes to the interior of the vehicle to be exposed toward a driver in the manual driving mode in which the driver is actively engaged in driving and a hide state in which the pedal pad is pushed behind a center fascia panel so that exposure toward the driver is blocked in the autonomous driving mode in which the driver is not actively engaged in driving, wherein a pressure-operated or liner motion signal generating portion generates a signal relating to a pedal function during manipulation of the pedal pad.