(EN)
An acceleration/deceleration erroneous operation determination device improves determination accuracy on whether or not a driver is erroneously performing an accelerator operation instead of a brake operation. A pedal opening degree by a driver and a continuation time for which the pedal opening degree is greater than an opening degree threshold value are detected. When the continuation time exceeds a time threshold value, it is determined that the driver is erroneously performing an accelerator operation instead of a brake operation. A vehicle speed of a vehicle, a rising gradient of a road surface, and an accelerator operation time operated by the driver are detected. The opening degree threshold value is made variable in accordance with the vehicle speed, the rising gradient, and the operation time. The time threshold value is made variable in accordance with the vehicle speed, the rising gradient, and the operation time.