This paper describes the behavior of metal-induced oxide charge (Q(m)i) in thermal oxide films (SiO2) grown on Al- or Fe-contaminated (100) silicon (Si) surfaces on the basis of the analysis by an surface photovoltage method. Al and Fe in SiO2 enhanced the oxide growth rate at an early stage of thermal oxidation, while they reduced it approximately 10% in several hundred minutes at 1123 K. During thermal oxidation, the Al and Fe existing in the native oxide were left behind at the surface of the SiO2. In Al- or Fe-contaminated and thermally oxidized p-type Si, the positive fixed oxide charge (Q(f)) was proved to be compensated for by the induction of a negative Q(mi) which was proposed by the conceptual model networks are formed in SiO2. As thermal oxidation proceeds, the negative Q(mi) has diminished. This is because the Al suboxides, which may be related to (AlOSi)(-) networks, in the thinnest oxides changed into Al2O3 in thicker oxide, resulting in a loss of negative charge. The Al-induced negative charge in SiO2 might enhance oxide growth at an early stage of oxidation by compensating the positive Q(i).