Provided is a position detection method using a first imaging unit and a second imaging unit that each capture an image of an object. The detection method may include: acquiring a first captured image with use of the first imaging unit; acquiring a second captured image with use of the second imaging unit; defining a position vector of the object based on the first captured image; calculating a first direction vector directed from the second imaging unit to the object with use of the defined position vector; calculating a second direction vector directed from the second imaging unit to the object based on the second captured image; and calculating a position of the object based on the first direction vector and the second direction vector.