An internal EGR control device for an internal combustion engine, which is capable of properly controlling an internal EGR amount, while causing conditions of burned gases to be reflected thereon in controlling the internal EGR by changing valve-closing timing of an exhaust valve. An internal EGR control device sets a target internal EGR amount EGRINCMD as a target of the internal EGR amount according to detected operating conditions of an internal combustion engine, and a target internal EGR amount EGRINC is determined by correcting the target internal EGR amount based on a gas state equation, using obtained temperature and pressure of exhaust gases, and a calculated gas constant R. Then, according to the corrected target internal EGR amount EGRINC, the valve-closing timing of an exhaust valve is calculated, and a variable valve mechanism is controlled based on the calculated valve-closing timing of the exhaust valve.