WINDMILL PITCH CONTROL DEVICE

A windmill pitch control device capable of performing feathering and continuing to generate electricity even at the time of a loss of an electricity supply capability of a main power source is provided. A motor controller 13 controls storage and discharge of electricity in and from an electricity accumulator 12, and controls an electric motor 11 based on a control signal for pitch control for changing the pitch angle of a blade 104 from a pitch controller 50 that transmits the control signal. An electricity accumulator operation monitoring portion 15 monitors an operational state of the electricity accumulator 12. The motor controller 13 is connected to a main power source 111 such that electricity is supplied to the motor controller 13. At the time of a loss of the electricity supply capability of the main power source 111, the motor controller 13 controls the electric motor 11 and continues the pitch control with electricity supplied from the electricity accumulator 12, based on the control signal. The control for changing the pitch angle of the blade 104 in a direction in which the wind pressure is reduced is performed based on a result of monitoring by the electricity accumulator operation monitoring portion 15.