An obstacle detection device includes an ultrasonic sensor, an obstacle detector to determine presence of an obstacle of interest if an intensity of a received ultrasonic wave exceeds a threshold value, and a threshold value setter to set a short-distance detection threshold value as the threshold value for the obstacle detection in a short-distance detection area in a vicinity of the ultrasonic sensor and to set a long-distance threshold value as the threshold value for the obstacle detection in a long-distance detection area located farther from the ultrasonic sensor than the short-distance detection area, the long-distance threshold value being less than the short-distance detection threshold value. The short-distance detection area is an area where variation in sound pressure distribution of transmitted ultrasonic waves is equal to or greater than the threshold value, and the long-distance detection area includes an area where the variation of the sound pressure distribution of transmitted ultrasonic wave is smaller than the threshold value.