To make the pulsation of the secondary pressure generated by a hydraulic booster (a booster) to the minimum.

The low pulsation hydraulic booster is provided with a plurality of plunger cylinders 2 having plungers 2a, and at the same time, to which a hydraulic output circuit is mutually connected; a plurality of hydraulic cylinders 1, which push the plungers 2a by the advancement of piston rods 1a by respectively connecting the piston rods 1a to the plungers 2a of the plunger cylinders 2, and at the same time, which draw the plungers 2a by the retreat of the piston rods 1a; and a controller 6 which makes the advancement and the retreat of each piston rod 1a of a plurality of the hydraulic cylinders 1 to repeat at the timing of mutually overlapping the time immediately before the finish of the advancement of the piston rod 1a of one hydraulic cylinder 1 and the time immediately after the start of the advancement of the piston rod 1a of the other hydraulic cylinder 1 in a set of two sequential hydraulic cylinders of a plurality of the hydraulic cylinders 1.