A buffer may include a first sensing unit configured to sense data, and a second sensing unit configured to generate equalization control signals according to outputs of the first sensing unit. The buffer may include an equalization delay compensation unit configured to compensate the equalization control signals for signal processing delay times of the equalization control signals, and generate delay-compensated equalization control signals. The buffer may include a noise removal unit configured to primarily remove noise of the output signals of the first sensing unit according to the equalization control signals, and secondarily remove noise of the output signals of the first sensing unit according to the delay-compensated equalization control signals.