Gas turbine plant and combined cycle plant

[Problem] To provide a gas turbine plant and a combined cycle plant with which the corrosion of a compressor due to cooling with sprayed water can be prevented by causing corrosive gases to be adsorbed and to accumulate in a filter provided within an air intake chamber of the compressor. [Solution] In a combined cycle plant (300A), an air intake filter (12) that adsorbs corrosive gases such as SOx and NOx is provided in an air intake chamber (102) of a compressor (1). In addition, a water-spraying device, wherein multiple water-spraying nozzles (115a) are provided in water-spraying network piping (115) which cools the intake air, is arranged downstream from the air intake filter (12) within the air intake chamber (102). Furthermore, a heating device wherein multiple air-spraying nozzles (132a) are provided in heated-air-spraying network piping (132) is installed upstream from the air intake filter (12), making it possible for the air intake filter (12) to be thermally regenerated. The time periods for air intake cooling and thermal regeneration of the air intake filter (12) are separated.