The invention relates to a stackable container that includes a lower part, base or bottom (1), two long lateral walls or side panels (2) and two short lateral walls or front panels (3) that include a flat element that can consist of two end base planks (10), of two pairs of cornered base planks (10') or one complete base plank (10") shaped such that when a plurality of containers are stacked, the bottom of an upper container (1) rests on the flat element (10, 10', 10") of a lower container. The flat element (10, 10', 10") acts as a support surface for an upper container when it is stacked and as a reinforcement of the container structure, giving it strength and avoiding breakage during stacking.