I will present a study of the multi-frequency properties of the Ultra Luminous Infrared Galaxy (ULIRG) IRAS 00183-7111 at z = 0.327, connecting ALMA sub-mm/mm observations with those at high energies, with the primary purpose to verify at what level the gas (traced by the CO) is responsible for the obscuration observed in X-rays (Ruffa et al. in prep.). Most of ULIRGs are known to host a heavily obscured AGN in its nuclear regions, and this fraction increases at increasing infrared luminosity. The detection of the most heavily obscured sources is crucial to shed light on the obscured accretion phase in black hole growth, the AGN/host galaxy co-evolution issue, and eventually estimate their contribution to the X-ray cosmic background. To link the sub-mm/mm to the X-ray properties of I00183, ALMA archival Cycle 0 data in Band 3 (87 GHz) and Band 6 (270 GHz) have been calibrated and analyzed, with the main goal to provide an improvement with respect to the available archival products and results. The high-energy data consists of Chandra, XMM-Newton and NuSTAR observations which allow a broad coverage of the spectrum in the energy range 0.5 − 30 keV. Chandra and XMM archival data were used, with an exposure time of 22 and 22.2 ks, respectively. The 100 ks NuSTAR are still private and the spectra were obtained by courtesy of the PI (K. Iwasawa). The main results show how the molecular gas in the central regions of I00183 can be considered responsible for a significant fraction of the AGN obscuration; further results, such a hint of an offset between the line and the continuum emission in ALMA Band 3 data, suggest interesting future perspectives for this work.