1. A registration method for registering a target registration object within reference orthogonal coordinates by using a single band-shaped registration mark formed on the target registration object, comprising: an intensity measurement step of receiving a mark image for a predetermined period of time by a two-dimensional storage type sensor while an area of the target registration object which includes the registration mark is illuminated, said two-dimensional storage type sensor having a plurality of elements which are two-dimensionally arranged within the reference orthogonal coordinates whose positional relationship within the reference orthogonal coordinates is known, of cumulatively storing electric charge stimulated by light of the mark image, and of measuring a light intensity of the mark image; a center position measurement process of measuring coordinates of a center position of the mark image associated with an arbitrary horizontal scanning line of the two dimensional storage type sensor on the basis of the light intensity obtained in said intensity measurement step; a mark center line calculation step of least square approximation of coordinates of said center position obtained in said center position measurement process and of obtaining a line passing through the center position drawn within the reference orthogonal coordinates; and a distance calculation step of calculating an intersection between a first baseline of the coordinates and the line obtained in said line calculation step, and a distance between an origin of coordinates and the line; wherein the line calculation step comprises: obtaining a line equation of a line passing through center positions of a mark image in accordance with least square approximation; calculating a displacement of said intersection from a second baseline, said second baseline being perpendicular to the axis of the scanning line; obtaining a slope and a displacement of the line with respect to the second baseline; obtaining positional data of the target registration object by utilizing the intensity measurement step, the center position measurement process, the mark center line calculation step and the distance calculation step; and moving the target registration object by an amount corresponding to the positional data.