Main results from the PAMELA space experiment after five years in flight

After five years of data taking in space, the experiment PAMELA is showing very interesting features in cosmic rays, namely in the fluxes of protons, heliums, electrons, that might change our basic vision of the mechanisms of production, acceleration and propagation of cosmic rays in the galaxy. In addition, PAMELA measurements of cosmic antiproton and positron fluxes are setting strong constraints to the nature of dark matter. PAMELA is also measuring the radiation environment around the Earth, and has recently discovered an antiproton radiation belt. In this paper PAMELA main results will be reviewed.