In a positional deviation detection apparatus provided with a transfer mechanism where plural arm portions are connected pivotably and in series with each other, the transfer mechanism being adapted to hold and transfer an object to be processed with a distal end arm portion, there are provided an edge detection unit that detects at least an edge of the object to be detected held by the distal end arm portion, the edge detection unit being provided in an arm portion among the plural arm portions, except for the distal end arm portion; and a positional deviation detection portion that obtains positional deviation of the object to be processed, in accordance with a detected value of the edge detection unit.