The present invention is a semiconductor integrated circuit device including a target circuit, a voltage supply circuit that supplies the power supply voltage to the target circuit, a control circuit that controls an output voltage of the voltage supply circuit, and a target voltage prediction circuit that predicts a voltage value of the power supply voltage. The control circuit changes the output voltage of the voltage supply circuit by a predetermined voltage value. The target voltage prediction circuit detects a change amount of an operating frequency of the target circuit along with the change of the predetermined voltage value, and calculates a target voltage value based on a relation between the change amount of the operating frequency and the predetermined voltage value. The voltage supply circuit supplies a power supply voltage corresponding to the target voltage value to the target circuit.