Disclosed is a solar assisted combined cycle power plant having a compressor that pressurizes combustion air, a combustor that mixes and burns the combustion air and gas turbine fuel to generate a high-temperature combustion gas, a gas turbine that drives the compressor by using the combustion gas, an exhaust heat recovery steam generator that obtains steam from thermal energy of a gas exhausted from the gas turbine, and a steam turbine that is driven by using the steam obtained by the exhaust heat recovery steam generator. The solar assisted combined cycle power plant includes a solar collector to turn supplied water to warm water; a heat accumulator that stores pressurized hot water from the solar collector and the exhaust heat recovery steam generator; and a spray device that handles the pressurized hot water as spray water and sprays the spray water onto the air to be taken into the compressor.