The paper presents the first results from the DAMA/LIBRA experiment, which uses a highly radiopure 250 kg NaI(Tl) detector set-up at the Gran Sasso National Laboratory. The experiment aims to detect Dark Matter (DM) particles through the model-independent annual modulation signature. The data collected over an exposure of 0.53 ton·year satisfy all the peculiarities of the DM annual modulation signature, with no systematic effects or side reactions accounting for the observed modulation amplitude. When combined with the previous DAMA/NaI data (total exposure of 0.82 ton·year), the presence of DM particles in the galactic halo is supported at 8.2σ confidence level. The modulation amplitude in the energy interval (2–6) keV is (0.0131 ± 0.0016) cpd/kg/keV, with a phase and period compatible with June 2nd and one year, respectively. The paper also discusses the absence of annual modulation in other energy regions and the results of a Fourier analysis, confirming the presence of a clear modulation in the lowest energy region. The analysis of multiple-hits events further supports the presence of a DM signal in the single-hit residuals, while the multiple-hits residual rate is compatible with zero, indicating no background modulation. The paper concludes that the DAMA/LIBRA data, combined with DAMA/NaI, provide strong evidence for the existence of DM particles in the galactic halo.The paper presents the first results from the DAMA/LIBRA experiment, which uses a highly radiopure 250 kg NaI(Tl) detector set-up at the Gran Sasso National Laboratory. The experiment aims to detect Dark Matter (DM) particles through the model-independent annual modulation signature. The data collected over an exposure of 0.53 ton·year satisfy all the peculiarities of the DM annual modulation signature, with no systematic effects or side reactions accounting for the observed modulation amplitude. When combined with the previous DAMA/NaI data (total exposure of 0.82 ton·year), the presence of DM particles in the galactic halo is supported at 8.2σ confidence level. The modulation amplitude in the energy interval (2–6) keV is (0.0131 ± 0.0016) cpd/kg/keV, with a phase and period compatible with June 2nd and one year, respectively. The paper also discusses the absence of annual modulation in other energy regions and the results of a Fourier analysis, confirming the presence of a clear modulation in the lowest energy region. The analysis of multiple-hits events further supports the presence of a DM signal in the single-hit residuals, while the multiple-hits residual rate is compatible with zero, indicating no background modulation. The paper concludes that the DAMA/LIBRA data, combined with DAMA/NaI, provide strong evidence for the existence of DM particles in the galactic halo.