An EGR flow rate control apparatus of an internal combustion engine is provided that can correct with high accuracy an EGR gas flow rate measured by a gas flow rate measurement apparatus in an EGR passage and control with high accuracy a gas flow rate regulating valve to reduce discharge amounts of PM and NOx in exhaust gases. An EGR flow rate control apparatus 10 of an internal combustion engine includes a gas flow rate correction unit 45 that corrects the EGR gas flow rate based on a first operating state parameter relating to pressure fluctuations of the intake pipe or exhaust pipe of the internal combustion engine and a second operating state parameter relating to a flow channel resistance of the EGR flow channel.