A control apparatus using a feedback control algorithm including an integral term, which is capable of controlling a controlled object having a response lag characteristic while suppressing influences of aging and sudden changes in an operating state, and thereby improving control accuracy. The control apparatus that controls a supercharger includes an ECU. The ECU calculates a reference FB target pressure using a first-order lag equation, an allowable upper limit value based on a value obtained by adding a predetermined allowable range value to the reference FB target pressure, an FB target pressure such that an actual boost pressure does not exceed the allowable upper limit value, and a feedback correction term using a PI control algorithm such that the actual boost pressure becomes equal to the FB target pressure, and controls the actual boost pressure using a driver demand boost pressure and the feedback correction term.