1. A position estimation apparatus comprising: a position estimation unit configured to estimate a position of a moving object driven on an arbitrary lane according to an image frame captured by a stereo camera provided in the moving object; a posture information acquisition unit configured to obtain first posture information of the moving object from the estimated position and second posture information of the moving object at a point of time of the stereo camera capturing the image frame; a position correction unit configured to calculate a probability distribution for a current position of the moving object by using the first posture information and the second posture information, configured to correct a first probability of the probability distribution for the current position as a corrected position of the moving object, configured to calculate a composite probability distribution based on a probability of a lane section of the arbitrary lane from a lane probability distribution chart and the corrected position output from the first position correction unit, and configured to re-correct a second probability of the composite probability distribution as a final position of the moving object.