We report a 40-Gb/s and highly accurate intensity limiter with a single Erbium-Doped Fiber Amplifier (EDFA) for low-power-consumption driving intensity limiting. The intensity limiter based on self-phase modulation with an appropriate pre-chirping procedure makes it possible, which provides a highly accurate limiting of less than 0.01dB. We fed 40-Gb/s signals with 2.69dB intensity fluctuation and 4.7dB improvement on the receiver sensitivity was obtained for a bit error rate of 10^-9 by using a numerical simulation.