Hot-carrier degradation on electrical characteristics of MOSFETs in the direct-tunneling regime of the gate oxide was investigated under a wide range of conditions, namely stress bias, oxide thickness, gate length, and channel-type dependence. It was confirmed that the transconductance degradation of n-MOSFETs with thinner gate oxides is smaller than that of thicker gate oxide MOSFETs, in spite of larger gate direct-tunneling leakage current and larger hot-carrier generation. For p-MOSFETs, little degradation was observed under all conditions of stress bias, oxide thickness, and gate length.