We report preliminary results of first $\theta_{13}$ measurements from the Double Chooz experiment with double-detector setup. In addition to the Far detector operation at ∼1 km baseline since 2011, we started the Near detector operation at ∼400 m baseline since beginning 2015, which allows us to reach significantly improved sensitivity of the neutrino mixing angle θ13. From oscillation analysis using rate and spectral shape, we obtained $\sin^22\theta_{13}$ = 0.111 $\pm$ 0.018 with $\chi^2$/ndf = 128.8/120, combining 1 year of double-detector and 2 years of single-detector data. We also reported current efforts to reach better sensitivity with improved analysis as well as other physics programs.