An internal voltage generator is disclosed. The internal voltage generator may include a comparator for controlling a voltage of a first node in response to a voltage difference between a reference voltage and an internal voltage, an internal voltage driving portion connected between a driving node and an internal voltage node to apply the internal voltage to the internal voltage node in response to a voltage level of the first node, and/or a leakage current interrupting portion to apply an external voltage to the first node to deactivate the internal voltage driving portion and to interrupt the external voltage applied to the driving node to interrupt a leakage current.