To shorten the working period by placing a work to be processed on a table, conducting correction of its positioning quickly, and eliminating the waiting time till the next stage of the processes.

A work to be processed 11 is placed on a table 12, and setting is made so that the work 11 faces a specified direction and takes the specified positioning. In this work locating method, the work 11 is provided with locating marks 11a and 11b and reference marks 12a and 12b are provided on the table 12 in its two places close to the locating marks 11a and 11b, and the coordinates for the closely positioned set of reference marks and locating marks are read simultaneously, followed by simultaneous reading of the coordinates for the other set, and from the acquired data, acknowledgement is made for the position of the work 11 with respect to the reference marks 12a and 12b on the table 12, and thus the location of the work 11 is conducted.