Photoluminescence spectra of ZnAl₂Se₄:Sm²⁺ due to the processes of charge carriers recombination from levels ⁵D_j, ⁵L_j, ⁵G_j and ⁵H_j (4f⁵5d¹) on levels ⁷Fj of samarium ions were investigated. The broad photoluminescence band at energies 1.6-1.9 eV due to optical transitions of electrons from 4f shell to 1s of samarium ions level was discovered. Emitted energy of it was absorbed by transitions from ⁷F_j to ⁵D_j levels. An up-conversion process - electron excitation from ⁷F_j levels to ⁵D₀, ⁵D₁, ⁵D₂ levels with simultaneous electron transitions to higher energy states ⁵D₃, ⁵D_4, ⁵L_j, ⁵G_j, ⁵H_j with subsequent recombination to ⁷F_j levels with energy emission in short-wavelength region were found out and investigated.