We present new experimental atomic transition values for the atomic emission spectrum of doubly ionized argon, Ar III. In this work we studied 3s² 3p4 - 3s² 3p³ 3d, 3s² 3p4 - 3s² 3p³ 4s, 3s² 3p4 - 3s² 3p³ 4d, 3s² 3p4 - 3s² 3p³ 5s, 3s² 3p³ 4p, and 3s² 3p³ 4p transition arrays and 196 lines were identified as new atomic transitions between levels of these configurations. The experimental data were obtained from a capillary-discharge tube. The identifications are supported by multiconfiguration Hartree-Fock relativistic calculations.