Studies of thick films (approximately 30 μm) of undoped zinc oxide on sapphire substrate obtained by magnetron sputtering method with the use of an uncooled target were conducted. The structural and luminescent properties of the initial films and films that underwent additional recrystallization annealing in the air were investigated. The time and temperature dependent characteristics of the samples were considered. It was shown that annealing in air leads to an improvement in the structural, optical, and luminescent properties of the obtained film.