An electron beam writing system, using discrete electron beams in which the interval of the beams is larger than the size of the beams, generates plural electron beams, on/off controls each of the electron beams according to pattern data to be written, and deflects the electron beams together, thereby performing writing on a wafer. One side of a unit writing area of the electon beams is larger than substantially twice the interval of the electron beams or substantially an integral multiple thereof.