This invention provides a low-current consumption type signal amplification circuit, which limits the output voltage to fix a lower-limit (upper-limit) saturation voltage of the amplification circuit at a predetermined lower-limit (upper-limit) limiting voltage. The signal amplification circuit comprises a negative feedback amplification circuit, a lower-limit voltage limiting circuit and an upper-limit voltage limiting circuit. The lower-limit voltage limiting circuit increases a resistance between an output terminal of the negative feedback amplification circuit and a ground terminal when the output voltage of the negative feedback amplification circuit falls below the lower-limit limiting voltage. The upper-limit voltage limiting circuit increases a resistance between the output terminal of the negative feedback amplification circuit and a high-potential side of a power supply when the output voltage of the negative feedback amplification circuit rises above the upper-limit limiting voltage.