1. An automatic tracking method, comprising detecting a light spot from a target supported on a moving object, taking a moving image of said target and said moving object, target tracking based on the detection of the light spot, performing image tracking based on said moving image in parallel to said target tracking, comparing a target position obtained by said target tracking with an image position obtained by said image tracking, and tracking based on a result of said target tracking in case where said target position and said image position are within a predetermined range.