The photoreduction of Sm³⁺ to Sm²⁺ was studied by a means of the nanosecond laser flash photolysis using a KrFexcimer laser with the oscillation wavelength of 248 nm. Sample was air-saturated methanol solution of 15-crown-5 with SmCl₃. The photoreduction occurred via a one-photon process. The reduction yield at 1 µs after the laser irradiation was estimated to be 0.37±0.05.