An ultrasonic sensor mounting structure includes an ultrasonic sensor and a wall member to which the ultrasonic sensor is mounted. The ultrasonic sensor includes an ultrasonic transducer and a vibrating surface. An inner surface of the wall member has a fixation portion where the ultrasonic sensor is fixed, a touch portion where the ultrasonic transducer touches, and a location mark portion that indicates location of the fixation portion. An outer surface of the wall member has a vibration portion as the vibrating surface of the ultrasonic sensor. The vibration portion is positioned opposite to the touch portion. The ultrasonic sensor can be accurately mounted in a desired location on the wall member without a reduction in a sensor characteristic, because the location mark portion does not overlap the touch portion. |