The invention relates to a capsule for the preparation of a beverage obtained by supplying hot water within the capsule under pressure and releasing the beverage from the capsule. The capsule includes a food substance therein, a first surface adapted to be traversed by a flow of water entering the capsule, and a second surface adapted to be traversed by a flow of beverage exiting the capsule. The second surface is adapted to deform outwardly upon action of the inside water pressure thereon. Also, that surface includes at least one opening member capable of deforming inwards the capsule upon a mechanical reaction force applied from outside onto the closure member as a result of the deformation of the second surface due to the build-up of the inside pressure.