A simple and high-reliability constitution provides a solid-state laser system that allows a high-output, long-pulse-width laser beam to be obtained.A solid-state laser system that includes a solid-state laser medium 1, a light source 2 for pumping the solid-state laser medium 1, two reflecting mirrors 3 and 4 for flanking the solid-state laser medium 1, thereby constituting a laser resonator, is constituted in such a manner that a virtual-mirror plane 5 is defined in the space between the solid-state laser medium 1 and the reflecting mirror 4; a lens 6 is provided between the virtual-mirror plane 5 and the reflecting mirror 4; and, by means of the forward and backward paths along the route from the virtual-mirror plane to the reflecting mirror by way of the lens, the virtual-mirror plane in the forward path and the virtual-mirror plane in the backward path are made in an optically conjugated relationship with each other.