An object is to provide a control device that calculates an intake pipe pressure of an engine, in which the humidity of air is measured, and a change in a gas constant due to a change in the total number of moles of air is corrected, to improve the accuracy of the calculation value of the intake pipe pressure.
A control device that controls an engine provided with an air amount measurement unit that measures an air amount passing through a throttle throttle valve provided in an intake passage of the engine, and a humidity measurement unit that measures a humidity of air passing through the throttle throttle valve, includes: an air amount calculation unit that calculates an air amount flowing into a cylinder of the engine based on a measurement result of the air amount measurement unit; and a pressure calculation unit that calculates a pressure of the intake manifold on a downstream side of the throttle throttle valve based on the air amount measured by the air amount measurement unit, the air amount calculated by the air amount calculation unit, and the humidity measured by the humidity measurement unit.