An obstacle detection device includes one or more emitter ultrasonic sensors, each emitting an ultrasonic wave toward an obstacle, and one or more detection ultrasonic sensors for reception, each detecting a reflected wave from the obstacle. A control unit drives a specific one of the emitter ultrasonic sensors to cause it to emit an ultrasonic wave, stops the emission of the ultrasonic wave by the specific emitter ultrasonic sensor at the time that one of the detection ultrasonic sensors detects a reflected wave from the obstacle, and carries out detection of the obstacle and measurement of the distance to the obstacle from the time that the control unit stops the emission of the ultrasonic wave by the emitter ultrasonic sensor and the time that the reflected wave cannot be detected anymore.