A desalination apparatus utilizing solar energy, and a method of operating the same. This apparatus is provided with a solar heat collector 12 for heating a heating medium 13 with solar energy, a heat exchanger 92 cooperating with an evaporation can 60 so as to subject the heating medium and raw water 62 in the evaporation can to heat exchange and generate water vapor 63 therein, a condenser 98 cooperating with a raw water tank 72 so as to receive the vapor 63 from the evaporation can, cool the vapor by subjecting the vapor and raw water in the raw water tank to heat exchange and obtain distilled water, a distilled water tank for storing distilled water, an evacuating means for evacuating the evaporation can and depressurizing the inside so as to promote the generation of vapor in the evaporation can, and a means for supplying raw water to the evaporation can. When a plurality of evaporation cans 60 are provided, a condenser cooperating with the evaporation cans is provided so as to receive the vapor 63 from an upstream-side evaporation can, cool the vapor with the raw water in a downstream-side evaporation can and thereby produce distilled water, and also heat the raw water in the downstream-side evaporation can and generate vapor.