A solid-state laser apparatus 1 bounces laser light L2 between an end mirror 3 and an output mirror 4 via a slab-type solid-state laser medium 2 excited by excitation light L1 to thereby amplify and output the laser light L2. The solid-state laser medium 2 includes incident/exit end faces 2a, 2b on and from which the laser light L2 is made incident and exits, and reflecting end faces 2c, 2d which reflect the laser light L2 so that the incident laser light L2 propagates in a zigzag manner. The incident/exit end face 2a is made incident with the excitation light L1 so that the excitation light L1 propagates along substantially the same propagation path as that of the laser light L2 within the solid-state laser medium 2. Accordingly, a solid-state laser apparatus which can improve the coupling efficiency between the excitation light and the laser light is realized.