Control Device for Internal Combustion Engine and Control Method for Internal Combustion Engine

An intake air flow rate into an intake passage is detected with an internal combustion engine as a control device, and atmospheric pressure and temperature are estimated or detected. An intake passage internal average pressure and an intake passage internal average temperature in a region up to a throttle valve of the intake passage as one region are estimated. Distributions of a pressure and a temperature inside the intake passage are estimated based on the estimated intake passage internal average pressure, the intake passage internal average temperature, and a model of energy change caused by a constituent element included in the intake passage.