A power generation amount prediction apparatus includes a first detector, acquisition unit, database, and controller. The first detector detects a measured value of the power generation amount of a photovoltaic power generation device. The acquisition unit acquires a predicted value of the power generation amount by the photovoltaic power generation device at specific times. The database stores the measured value and the predicted value for each of the specific times for a plurality of days. The controller calculates a corrected predicted value for each of the specific times based on a maximum measured value, a maximum predicted value, and a predicted value newly received by the acquisition unit. The maximum measured value and the maximum predicted value are respectively the maximum value, for each of the specific times, of the measured value and of the predicted value for a predetermined number of days.