A shock absorber includes a piston joined to a piston rod that proceeds into and recedes from a cylinder, an extension-side chamber and a compression-side chamber that are separated from each other by the piston and have a working fluid reserved therein, first and second extension-side discharge passages in which the working fluid discharged from the extension-side chamber flows, an extension-side supply passage in which the working fluid to be supplied to the compression-side chamber flows, first and second compression-side discharge passages in which the working fluid discharged from the compression-side chamber flows, and a compression-side supply passage in which the working fluid to be supplied to the extension-side chamber flows. An extension-side damping valve and a compression-side damping valve are respectively provided in the first extension-side discharge passage and the first compression-side discharge passage. An extension-side electromagnetic pressure control valve and a compression-side electromagnetic pressure control valve, which are respectively provided in the second extension-side discharge passage and the second compression-side discharge passage, are set such that the openings thereof are maximized before the piston speed reaches a high-speed range.