An apparatus for controlling an EGR valve, the apparatus comprising: a measurement unit configured to measure at least one operation condition of an engine system; a fresh air amount setting unit configured to set a target amount of fresh air based on the operation condition; a fresh air amount sensor configured to measure a current amount of fresh air introduced through an intake line; an identifier configured to simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve; a gain setting unit configured to set at least one gain according to an operation condition of the engine system; and a control calculation unit configured to correct the gain in accordance with the operation condition of the engine system by dividing the gain by the engine system input-output sensitivity, compare the target amount of fresh air with the current amount of fresh air to calculate a control error (e), and use the corrected gain and the calculated control error (e) for its calculations to output a control signal for controlling the opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air. a measurement unit configured to measure at least one operation condition of an engine system; a fresh air amount setting unit configured to set a target amount of fresh air based on the operation condition; a fresh air amount sensor configured to measure a current amount of fresh air introduced through an intake line; an identifier configured to simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve; simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve; a gain setting unit configured to set at least one gain according to an operation condition of the engine system; and a control calculation unit configured to correct the gain in accordance with the operation condition of the engine system by dividing the gain by the engine system input-output sensitivity, compare the target amount of fresh air with the current amount of fresh air to calculate a control error (e), and use the corrected gain and the calculated control error (e) for its calculations to output a control signal for controlling the opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air. correct the gain in accordance with the operation condition of the engine system by dividing the gain by the engine system input-output sensitivity, compare the target amount of fresh air with the current amount of fresh air to calculate a control error (e), and use the corrected gain and the calculated control error (e) for its calculations to output a control signal for controlling the opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air.