A distance measurement system for modulating a light emitted from a light source (21), which emits a coherent light, into frequencies different from each other to measure an object under measurement, characterized in that it includes: a first means (23) for modulating the light emitted from the light source (21) into two lights which have frequencies different from each other and are irradiated separately adjacent to each other; a second means (26) for one-dimensionally or two-dimensionally scanning the two lights; a third means (31) for irradiating an object under measurement with the two lights which are two-dimensionally scanned; a fourth means (29) for receiving at least two or more divided reflected lights or transmitted lights from the object under measurement with a boundary line being interposed therebetween in a direction substantially perpendicular to the direction in which the two lights are separated; a fifth means (33) for generating a difference signal or a summation signal of respective outputs of the lights received by the fourth means (29) in areas with the boundary line being interposed therebetween; and a sixth means (34) for obtaining a phase difference or an intensity difference of the difference signal or the summation signal to obtain a measurement value.