Object: To provide a solar light pumped laser and a cooling method of a solar light pumped laser.Means for Solving the Problems: A solar light pumped laser performing laser oscillation by pumping a laser medium with solar light, the solar light pumped laser including, a laser medium 12, a container device 14 that supports the laser medium 12 therein, the container device 14 being provided with a focusing optical element 22 for irradiating solar light focused along the laser medium 12, while retaining cooling liquid in a space between the laser medium 12 and the container device 14, and additionally, a pair of optical reflection elements (16, 18) arranged adjacent to the opposing ends of the laser medium. An end of the container device 14 has Brewster's angle. Further, the cooling liquid according to the present invention contains water functioning as an optical medium to form a water lens simultaneously with cleaning the focusing optical element 22.