An engine control apparatus to control an engine, the apparatus comprising: a first controller configured to generate first and second instruction values to adjust an MAF, Mass Air Flow, of fresh air supplied to the engine and an MAP, Manifold Absolute Pressure, indicating a pressure of air supplied to the engine to respective target values, based on measured values of a first sensor which detects the MAF and a second sensor which detects the MAP, regardless of limiting conditions related to a totally closed state or a fully open state of an EGR, Exhaust Gas Recirculator which adjusts an amount of exhaust recirculated to the engine and a VNT, Variable Nozzle Turbo which adjusts an amount of exhaust output to an outside of the engine; a second controller configured to generate the first and second instruction values to adjust the MAF and the MAP to the respective target values, based on the measured values of the first and second sensors, under the limiting conditions; a saturation detector configured to issue a switch instruction instructing switching of control from the first controller to the second controller when the saturation detector detects saturation of the first or second instruction value generated by the first controller; and a switch configured to supply the measured values of the first and second sensors to the first controller when no switch instruction is received, and to switch a supplying destination of the measured values of the first and second sensors from the first controller to the second controller for a certain time after receiving the switch instruction, wherein the second controller is further configured, for a certain time after the control is switched from the first controller to the second controller, to assume that the instruction value indicating a manipulated variable for a valve of the EGR or a nozzle of the VNT is constant. a first controller configured to generate first and second instruction values to adjust an MAF, Mass Air Flow, of fresh air supplied to the engine and an MAP, Manifold Absolute Pressure, indicating a pressure of air supplied to the engine to respective target values, based on measured values of a first sensor which detects the MAF and a second sensor which detects the MAP, regardless of limiting conditions related to a totally closed state or a fully open state of an EGR, Exhaust Gas Recirculator which adjusts an amount of exhaust recirculated to the engine and a VNT, Variable Nozzle Turbo which adjusts an amount of exhaust output to an outside of the engine; a second controller configured to generate the first and second instruction values to adjust the MAF and the MAP to the respective target values, based on the measured values of the first and second sensors, under the limiting conditions; a saturation detector configured to issue a switch instruction instructing switching of control from the first controller to the second controller when the saturation detector detects saturation of the first or second instruction value generated by the first controller; and a switch configured to supply the measured values of the first and second sensors to the first controller when no switch instruction is received, and to switch a supplying destination of the measured values of the first and second sensors from the first controller to the second controller for a certain time after receiving the switch instruction, wherein the second controller is further configured, for a certain time after the control is switched from the first controller to the second controller, to assume that the instruction value indicating a manipulated variable for a valve of the EGR or a nozzle of the VNT is constant.