A feedback control method of a control device including a delay compensator including a filter (4, 5) and a model of a control target having a nominal plant model and a nominal model of a delay element, a first feedback controller, a notch filter, and a disturbance compensator, wherein the delay compensator receives an operation amount for the control target as an input, causes the filter (4, 5) to operate on an error calculated from an output of the control target with respect to the operation amount and an output of the model of the control target with respect to the operation amount, and calculates an output of the delay compensator based on an operation result of the filter (4, 5) and an output of the nominal plant model with respect to the operation amount, the notch filter is provided after the first feedback controller so as to process an output of the first feedback controller, the filter (4, 5) is configured as a function of a second feedback controller corresponding to the nominal plant model and the model of the control target so that delay compensation can be stably performed even when the control target has a pole at an origin, the filter (4, 5) is decomposed into a first filter (Np, 5) and a second filter (Nd, 4), in the first filter (Np, 5), a round-trip transmission characteristic is given by a product of the model of the control target and the second feedback controller, and an open-loop characteristic is given by a closed-loop system transmission characteristic configured such that an output is equivalent to an input, in the disturbance compensator, an output of the first filter (Np, 5) is processed by a third feedback controller, and an output of the third feedback controller is an output of the disturbance compensator, and the first feedback controller performs feedback compensation on the control target based on a deviation between the output of the delay compensator and a target value, and calculates the operation amount for the control target based on an output of the notch filter and the output of the disturbance compensator. wherein the delay compensator receives an operation amount for the control target as an input, causes the filter (4, 5) to operate on an error calculated from an output of the control target with respect to the operation amount and an output of the model of the control target with respect to the operation amount, and calculates an output of the delay compensator based on an operation result of the filter (4, 5) and an output of the nominal plant model with respect to the operation amount, the notch filter is provided after the first feedback controller so as to process an output of the first feedback controller, the filter (4, 5) is configured as a function of a second feedback controller corresponding to the nominal plant model and the model of the control target so that delay compensation can be stably performed even when the control target has a pole at an origin, the filter (4, 5) is decomposed into a first filter (Np, 5) and a second filter (Nd, 4), in the first filter (Np, 5), a round-trip transmission characteristic is given by a product of the model of the control target and the second feedback controller, and an open-loop characteristic is given by a closed-loop system transmission characteristic configured such that an output is equivalent to an input, in the disturbance compensator, an output of the first filter (Np, 5) is processed by a third feedback controller, and an output of the third feedback controller is an output of the disturbance compensator, and the first feedback controller performs feedback compensation on the control target based on a deviation between the output of the delay compensator and a target value, and calculates the operation amount for the control target based on an output of the notch filter and the output of the disturbance compensator.