Supernova SN1987A in the Large Magellanic Cloud offers an unprecedented opportunity to research on fundamental issues of supernova explosions: dust and molecule formation, interaction with the circumstellar medium, particle acceleration, pulsar formation, etc. Since 2011, instruments like ALMA have been fundamental for such endeavor. Tomographic techniques have recently permitted to obtain 3D-images of the molecular emission and high resolution maps of dust emission are now available. Those results, compared with predictions from hydro-dynamical simulations, are paving the way to a better understanding of supernovae explosions. In the talk, the main results will be highlighted with emphasis in the advances produced since 2017 in the understanding of the structure of the inner ejecta.