A microstructure including in a first layer insulated from a substrate by an insulator layer at least one sensitive element connected to at least one contact pad by an electrical connection and protected by a package cap. The sensitive element, the electrical connection, and the contact pad form an assembly delimited in the first layer by at least one trench, the assembly being covered by the package cap. The package cap includes at least one opening above the contact pad and is integral with the contact pad on the edges of the opening and with a zone located beyond the trench in relation to the assembly. Such a microstructure can find application in particular in microelectromechanical structures.