Abstract: An overhead wire mutual separating situation measuring apparatus detects separation of overhead wires with high accuracy in a manner that the overhead wires are placed with a predetermined amount of deviation. A light projecting unit irradiates overhead wires above a railway with a measuring light spreading in a strip shape in the width direction of the railway. Light receiving units receive light reflected by all or a portion of the overhead wires from the measuring light to output a measurement signal indicative of a contour of the overhead wires. Each light receiving unit mutually partially overlaps a measurement area such that the overhead wires within a predetermined measurement area fall within the measurement visual area of at least one light receiving unit. The processing device processes the measurement signal from each light receiving unit to detect a mutual separation of the overhead wires and the positional deviation thereof.