A wind power generation device includes a blade, a main shaft of which one end is connected to the blade, a speed increaser connected to the other end of the main shaft, an output shaft of which one end is connected to the speed increaser, a power generation unit connected to the other end of the output shaft, a vibration sensor, and an abnormality diagnosis unit. The power generation unit is configured to rotate the output shaft and the main shaft by performing powering operation. The abnormality diagnosis unit diagnoses the presence or absence of an abnormality based on data acquired by the vibration sensor during a period in which the power generation unit performs powering operation.