To provide an internal potential generation circuit which can reduce its power consumption and also can suppress the fluctuation of its threshold voltage that is caused by the process variance.

An internal potential detection circuit part 3 consists of a reference voltage generation circuit part 4 and a MOS transistor TR 5. The part 4 is connected to the gate of the TR 5 and applies the generated reference voltage Vr of a constant level to the gate of the TR 5. The source of the TR 5 is grounded and the source-gate voltage of the TR 5 is kept at a constant level. The back gate of the TR 5 is connected to a voltage supply part 2, and the potential of the part 2 is applied to the back gate of the TR 5. When the potential of the part 2 rises, the back gate potential of the TR 5 also rises and the threshold voltage of the TR 5 drops.