A low-dropout regulator includes: a first operational amplifier having a first input receiving an input voltage; a first P-channel MOSFET having a gate connected to an output of the first operational amplifier, a source connected to a power source terminal, and a drain connected to an output terminal; a feedback circuit providing at least portion of a voltage of the output terminal as a feedback to a second input of the first operational amplifier; and a triode limiter circuit receiving voltages at the source and the gate of the first P-channel MOSFET comparing a voltage difference therebetween with a predetermined reference voltage, and increasing a voltage of the second input of the first operational amplifier when the voltage difference is the same as the reference voltage.