The semiconductor circuit device includes a power line receiving first voltage; each of internal circuits being provided with different operating voltages by the operation mode; a power supply circuit connected with one of internal circuits and the power line to provide second voltage lower than the first voltage to the one of internal circuits; and a control circuit controlling the power supply circuit in accordance with each of the operation modes, wherein when a change of a operation mode is performed, if a operating voltage after the change of a operation mode is higher than a operating voltage before the change of a operation mode, firstly the control circuit controls the power supply circuit to supply a second voltage higher than the operating voltage and secondly the control circuit controls the power supply circuit to supply the operation voltage after the change of a operation mode to the internal circuit.