A communication apparatus encodes a transmission target data according to a PAM5 mode to generate PAM signals, applies a pulse shaping to the generated PAM signals with a pulse shaping filter to provide pulse-shaped PAM signals, and inputs the pulse-shaped PAM signals into a digital-analog converter. The pulse shaping filter designates a transfer function G(z) as G1(z)=0.667+0.333z^−1 that is approximated to G0(z)=(⅔)+(⅓)z^−1.