Internal combustion engine control apparatus

An internal combustion engine control apparatus includes a turbocharger (21), an intake air quantity detecting section, an intake air pressure detecting section, a turbine rotational speed limit determining section and a turbine control section. The turbine rotational speed limit determining section determines a turbine rotational speed limit pressure ratio (Pratio_Comp_limit) between the upstream-side intake air pressure (P_in_Comp) and a downstream-side intake air pressure (P_out_Comp) in the air intake passage (3) at a downstream side of the compressor (23) for a turbine rotational speed limit that corresponds to the intake air quantity (Gair) detected by the intake air quantity detecting section. The turbine rotational speed limit determining section further calculates a turbine over rotation suppressing boost pressure (P_out_Comp_limit) of the turbine compressor (23) using the upstream-side intake air pressure (P_in_Comp) and the turbine rotational speed limit pressure ratio (Pratio_Comp_limit). The turbine control section controls the turbocharger (21) based on the turbine over rotation suppressing boost pressure (P_out_Comp_limit).