1. An object position estimation device, comprising: an object candidate acquisition unit for estimating object positions by a visual cone intersection method and acquires candidate objects; an object candidate information storage means which stores information on overlap among said candidate objects for a visual cone of objects which is acquired based on a captured image; a degree of co-movement acquisition unit for acquiring a degree of co-movement of said candidate objects which is calculated based on number of visual cones including other candidate objects which co-move with the movement of said candidate objects, or a degree of confidence acquisition unit for acquiring a degree of confidence of said candidate objects which is calculated based on number of visual cones which an overlap condition determining means determined that there is an overlap of said candidate objects with other candidate objects; and a candidate object determination unit for identifying said candidate objects as either objects or non-objects by a posteriori probability which is calculated based on acquired said degree of co-movement or said degree of confidence and outputs position of said candidate objects which is determined as objects.