A control device (10, 10A) comprising: a setting part configured to set a PID value including a proportional band (Pb) and an integral time (Ti) and filter coefficients α and β of two-degree-of-freedom PID control; the control device (10, 10A) being characterized in further comprising: a target value filter configured to calculate an internal target value (VLti) from a target value (VLt) of control using the filter coefficients α and β set by the setting part, wherein the internal target value (VLti) is calculated by the following expression: VLti = 1 + αβ Tis / 1 + α Tis; and a PID control part configured to calculate an amount of operation for control using the PID value set by the setting part and the internal target value (VLti) calculated by the target value filter as input, wherein the setting part sets the filter coefficients α and β using the target value (VLt), an initial value (VLs) at a start time of control of the target value (VLt), and the proportional band (Pb), wherein the setting part sets the filter coefficient α using the target value (VLt), the initial value (VLs), the proportional band (Pb), and the integral time (Ti), and sets the filter coefficient β using the target value (VLt), the initial value (VLs), and a ratio of the proportional band (Pb) and the integral time (Ti). a setting part configured to set a PID value including a proportional band (Pb) and an integral time (Ti) and filter coefficients α and β of two-degree-of-freedom PID control; the control device (10, 10A) being characterized in further comprising: a target value filter configured to calculate an internal target value (VLti) from a target value (VLt) of control using the filter coefficients α and β set by the setting part, wherein the internal target value (VLti) is calculated by the following expression: VLti = 1 + αβ Tis / 1 + α Tis; and a PID control part configured to calculate an amount of operation for control using the PID value set by the setting part and the internal target value (VLti) calculated by the target value filter as input, wherein the setting part sets the filter coefficients α and β using the target value (VLt), an initial value (VLs) at a start time of control of the target value (VLt), and the proportional band (Pb), wherein the setting part sets the filter coefficient α using the target value (VLt), the initial value (VLs), the proportional band (Pb), and the integral time (Ti), and sets the filter coefficient β using the target value (VLt), the initial value (VLs), and a ratio of the proportional band (Pb) and the integral time (Ti). a target value filter configured to calculate an internal target value (VLti) from a target value (VLt) of control using the filter coefficients α and β set by the setting part, wherein the internal target value (VLti) is calculated by the following expression: VLti = 1 + αβ Tis / 1 + α Tis; and a PID control part configured to calculate an amount of operation for control using the PID value set by the setting part and the internal target value (VLti) calculated by the target value filter as input, wherein the setting part sets the filter coefficients α and β using the target value (VLt), an initial value (VLs) at a start time of control of the target value (VLt), and the proportional band (Pb), wherein the setting part sets the filter coefficient α using the target value (VLt), the initial value (VLs), the proportional band (Pb), and the integral time (Ti), and sets the filter coefficient β using the target value (VLt), the initial value (VLs), and a ratio of the proportional band (Pb) and the integral time (Ti).