There is provided a press machine which can apply a large compression force to a mold as well as impart smooth vibration only in a rectilinear advancing direction to the mold, and thereby can improve the press-formability. A main slide and a sub-slide constitute a slide and at the same time a cylinder-piston mechanism. During press-forming, a compression force is transmitted to the sub-slide (an upper mold) through hydraulic pressure applied interlockingly with driving of the main slide, and the sub-slide is vibrated with the hydraulic pressure being periodically changed. Favorable press-forming can be performed even under relatively difficult press-forming conditions, by controlling the vibration such that a vibration frequency of the sub-slide (the upper mold) becomes 9 Hz or higher but 33.3 Hz or lower and a vibration amplitude of the sub-slide becomes 0.05 mm or larger but 0.5 mm or smaller.