We have studied the pressure-induced superconductivity in an antiferromagnet CeRh₂Si₂ by measuring the electrical resistivity for a high-quality single crystal. The superconducting resistivity drop was observed around P_c \simeq 1.06 GPa, at which the Néel temperature becomes zero, namely in a pressure region from 0.97 to 1.20 GPa. The zero resistivity appears below 0.4 K between 1.03 to 1.08GPa. The resistivity at low temperatures follows the Fermi liquid AT² relation in the whole pressure region, even at P_c. The A value becomes a maximum around P_c.

PACS numbers: 71.27.+a, 74.62.Fj, 74.70.Tx