A microdevice encapsulation structure arranged in at least one cavity formed between a substrate and a cap rigidly attached to the substrate is provided, the cap including one layer of a first material, one face of which forms an inner wall of the cavity, and mechanical reinforcement portions rigidly attached at least to and partly covering said face, having gas absorption and/or adsorption properties, in which the Young's modulus of a second material of the mechanical reinforcement portions is higher than that of the first material, wherein each of said portions includes at least one first layer of the second material, and at least one second layer of a third metallic getter material such that the first layer of the second material is arranged between the layer of the first material and the second layer of the third material and/or is covered by the second layer of the third material.