This obstacle detection device comprises: an ultrasonic sensor; an obstacle detection unit that detects an obstacle when the intensity of a received ultrasonic wave exceeds a threshold value; and a threshold value setting unit that sets a short distance threshold value as the threshold value used for obstacle detection in a short distance detection area located in the vicinity of the ultrasonic sensor, and sets a long distance threshold value lower than the short distance threshold value as the threshold used for obstacle detection in a long distance detection area farther removed from the ultrasonic sensor in comparison to the short distance detection area. The short distance detection area is an area wherein the dispersion of the sound pressure distribution of transmitted ultrasonic waves is at least a prescribed value, and the long distance detection area is an area wherein the dispersion of the sound pressure distribution of transmitted ultrasonic waves is less than the prescribed value.