An electric-power-generating-facility operation management support system includes an analyzing unit that calculates operation plan creating basic information based upon received information with regard to lifespan calculating expressions, present electric-power market information, and operation-history information with regard to an electric power generation. The electric-power-generating-facility operation management support system also includes an operation plan creating unit that calculates and outputs operational conditions of electric power generating facilities as a created operation planning based upon the operation plan creating basic information calculated by the analyzing unit. The analyzing unit includes a lifespan-consumption-costs calculating unit that calculates lifespan consumption costs of the electric power generating facilities. In addition, the analyzing unit includes a reserve-electric-power-price estimating unit that estimates a market price of reserve electric power. The analyzing unit further includes a reserve-electric-power supply -probability estimating unit that estimates a probability of a supply of the reserve electric power.