A power generation controller of an aircraft, the power generation controller being configured to control a hydraulic transmission configured to change speed of rotational power of an aircraft engine and transmit the rotational power to a power generator, the hydraulic transmission being a toroidal continuously variable transmission, the power generation controller comprising: a low-temperature start-up control section configured to, when it is determined that an oil temperature of a hydraulic actuator configured to change an operation position of a speed change element of the hydraulic transmission satisfies a predetermined low-temperature condition when starting up the aircraft engine, set the power generator to a power non-generating state and control the hydraulic actuator such that the speed change element is positioned at an acceleration side of a median in a speed change range; and a power generation control section configured to, when it is determined that the oil temperature satisfies a predetermined low-temperature start-up completion condition, set the power generator to a power generating state and control the hydraulic actuator in accordance with a rotational frequency of the aircraft engine. the power generation controller being configured to control a hydraulic transmission configured to change speed of rotational power of an aircraft engine and transmit the rotational power to a power generator, the hydraulic transmission being a toroidal continuously variable transmission, the power generation controller comprising: a low-temperature start-up control section configured to, when it is determined that an oil temperature of a hydraulic actuator configured to change an operation position of a speed change element of the hydraulic transmission satisfies a predetermined low-temperature condition when starting up the aircraft engine, set the power generator to a power non-generating state and control the hydraulic actuator such that the speed change element is positioned at an acceleration side of a median in a speed change range; and a power generation control section configured to, when it is determined that the oil temperature satisfies a predetermined low-temperature start-up completion condition, set the power generator to a power generating state and control the hydraulic actuator in accordance with a rotational frequency of the aircraft engine. a low-temperature start-up control section configured to, when it is determined that an oil temperature of a hydraulic actuator configured to change an operation position of a speed change element of the hydraulic transmission satisfies a predetermined low-temperature condition when starting up the aircraft engine, set the power generator to a power non-generating state and control the hydraulic actuator such that the speed change element is positioned at an acceleration side of a median in a speed change range; and a power generation control section configured to, when it is determined that the oil temperature satisfies a predetermined low-temperature start-up completion condition, set the power generator to a power generating state and control the hydraulic actuator in accordance with a rotational frequency of the aircraft engine.