SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

PROBLEM TO BE SOLVED: To reduce current consumption without deteriorating the processing performance. SOLUTION: For the voltage level of back gate voltages VGP and VGN supplied to the back gate of MOS transistors P1, P2, N1 and N2 provided in an internal circuit 1, a voltage specified by selection signals among voltage generation circuits 2a, 2b, 4a and 4b for generating the voltages of the plural different voltage levels is selected, corresponding to the selection signals SELp and SELn corresponding to an operation mode from a mode detection circuit 10. The threshold voltage and drive current amount of the MOS transistor are adjusted, corresponding to the operation mode, and this semiconductor integrated circuit device operated at a high speed with the low current consumption is realized.