A throttle valve for preventing a sudden unintended acceleration, the throttle valve regulating an amount of air supplied to an engine mounted on a vehicle and including a valve main body, a flow path formed in the valve main body and having an inlet through which the air flows in and an outlet connected to the engine, and a flow rate regulating unit regulating an amount of the air in the flow path by opening or closing the flow path, in which, when a rapid pressure drop occurs at the outlet side connected to the engine, the flow rate regulating unit is pressed by a force generated due to a difference in pressure between the inlet and the outlet so as to close the flow path without use of an additional drive source. When a rapid pressure drop occurs at the outlet side connected to the engine, a flow rate regulating unit automatically closes the flow path without use of an additional drive source by being pressed by a force generated due to a difference in pressure between the inlet and the outlet, thereby substantially preventing a vehicle sudden unintended acceleration accident.