PROBLEM TO BE SOLVED: To provide a low-cost automatic positioning working machine which is of a simple mechanical structure and saves its installation space. SOLUTION: This automatic positioning working device comprises a variety of working machines 7, a body 8 consisting of these working machines 7 installed in a row, a clamping device 6 which retains a work 1 in a freely rotatable manner and a drive device 5 which moves the clamping device 6 relatively. In addition, at the lower part of the body 8, two pairs of centering bodies 13, each pair of which is provided symmetrically to the right/left and in a rocking manner, two pairs of horizontally centering members 2, each pair of which is mounted, in an individually projecting/retracting manner, to the two pairs of the centering bodies 13 and an upper end stopper 14 which limits the upper end position of each of the horizontally centering members 2. The two pairs of the centering bodies 13 are equipped with an elevator device 15 and a part 3, for receiving the work 1, to which the tip of the elevator part 15a is connected and which is provided on the two pairs of horizontally centering members 2 respectively. Further, a linkage member 17 is provided which links each of the parts 3 to each pair of the members 2 and narrows the interval of each pair of the members 2.
