1. A camera parameter calibration apparatus comprising: a 3D space manager which generates a 3D object of preset size represented on a 3D space according to a parameter related to a visual point and changes the parameter according to an external control; an image combiner which combines the 3D object generated by the 3D space manager with an image provided from an external image source and displays the combined 3D object and image at once; and a setting manager which stores the parameter set by the 3D space manager in association with the external image source.