An object detection device comprising: a transmission unit for transmitting a transmission wave to a detection range; a first reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; a second reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; a third reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; and a determination unit for determining presence or absence of an object to be avoided, based on outputs of the first reception unit, the second reception unit, and the third reception unit, wherein the determination unit calculates first coordinates at which an object is estimated to be present, based on a first reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the first reception unit, and a second reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the second reception unit, calculates second coordinates at which an object is estimated to be present, based on the second reception time, and a third reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the third reception unit, and compares a distance between the first coordinates and the second coordinates with a prescribed reference distance, determines that an object is the object to be avoided in a case where the distance between the first coordinates and the second coordinates is less than the reference distance, and determines that an object is not the object to be avoided in a case where the distance between the first coordinates and the second coordinates is equal to or larger than the reference distance. a transmission unit for transmitting a transmission wave to a detection range; a first reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; a second reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; a third reception unit for receiving a reflected wave resulting from reflection of the transmission wave transmitted from the transmission unit by an object within the detection range; and a determination unit for determining presence or absence of an object to be avoided, based on outputs of the first reception unit, the second reception unit, and the third reception unit, wherein the determination unit calculates first coordinates at which an object is estimated to be present, based on a first reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the first reception unit, and a second reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the second reception unit, calculates second coordinates at which an object is estimated to be present, based on the second reception time, and a third reception time from when the transmission unit transmits a transmission wave until a reflected wave is received by the third reception unit, and compares a distance between the first coordinates and the second coordinates with a prescribed reference distance, determines that an object is the object to be avoided in a case where the distance between the first coordinates and the second coordinates is less than the reference distance, and determines that an object is not the object to be avoided in a case where the distance between the first coordinates and the second coordinates is equal to or larger than the reference distance.