A small X-ray laser generator including a device (1) for generating and accelerating an electron beam, a plurality of targets (2) placed on the transport trajectory of a generated electron beam (4), and X-ray mirrors (3) for monochromatizing X-rays (5) generated by making the electron beam (4) collide against the plurality of targets (2), in which the X-rays (6) generated from the respective targets (2) are made to interfere with each other to produce a hard X-ray laser beam of 1 keV or more.