Upon satisfaction of an idle learning condition, the internal combustion engine system of the invention successively performs learning of an idle control amount and learning of a most delayed angle control amount in this sequence. Upon satisfaction of a most delayed angle learning condition, on the other hand, the internal combustion engine system successively performs learning of the most delayed angle control amount and learning of the idle control amount in this sequence. This arrangement effectively reduces the total time required for completion of learning both the idle control amount and the most delayed angle control amount, compared with the conventional procedure of individually learning only one control amount corresponding to the satisfied learning condition.