A bag for keeping fruits and vegetables hydrated, comprising: a laminar body made of polymer material including: a first layer of material having structural functions, the first layer being of rectangular shape and being folded along a width direction thereof in six sections along two respective external fold lines (C, C'), two respective intermediate fold lines (B, B') and a central fold line, the external fold lines (C, C') defining a central portion and two edge portions of the first layer, the central portion being provided with perforations in the areas between respective intermediate fold lines (B, B') and the external fold lines (C, C') as well as in an area between the intermediate fold lines (B, B') which forms a planar base of the bag a second layer made of non-woven fabric material or a micro-perforated polymer material, the second layer being placed above the first layer in the central portion between the external fold lines (C, C'); and a third layer made of micro-perforated polymer material, placed above the second layer and located between the external fold lines (C, C'), wherein the second and third layers are heat-sealed to the first layer only at edges thereof in the external fold lines (C, C'). a laminar body made of polymer material including: a first layer of material having structural functions, the first layer being of rectangular shape and being folded along a width direction thereof in six sections along two respective external fold lines (C, C'), two respective intermediate fold lines (B, B') and a central fold line, the external fold lines (C, C') defining a central portion and two edge portions of the first layer, the central portion being provided with perforations in the areas between respective intermediate fold lines (B, B') and the external fold lines (C, C') as well as in an area between the intermediate fold lines (B, B') which forms a planar base of the bag a second layer made of non-woven fabric material or a micro-perforated polymer material, the second layer being placed above the first layer in the central portion between the external fold lines (C, C'); and a third layer made of micro-perforated polymer material, placed above the second layer and located between the external fold lines (C, C'), a first layer of material having structural functions, the first layer being of rectangular shape and being folded along a width direction thereof in six sections along two respective external fold lines (C, C'), two respective intermediate fold lines (B, B') and a central fold line, the external fold lines (C, C') defining a central portion and two edge portions of the first layer, the central portion being provided with perforations in the areas between respective intermediate fold lines (B, B') and the external fold lines (C, C') as well as in an area between the intermediate fold lines (B, B') which forms a planar base of the bag a second layer made of non-woven fabric material or a micro-perforated polymer material, the second layer being placed above the first layer in the central portion between the external fold lines (C, C'); and a third layer made of micro-perforated polymer material, placed above the second layer and located between the external fold lines (C, C'), wherein the second and third layers are heat-sealed to the first layer only at edges thereof in the external fold lines (C, C').