An interface element (20) for a testing apparatus of electronic devices comprises at least one support (21) provided with a plurality of through-openings (22) that house respective interconnections elements (23), which extend between a first end (23a) and a second end (23b). Suitably, the interconnections elements (23) are made of a conductive elastomer that fills the openings (22) of the support (21), each of the interconnection elements (23) forming a conductive channel between different and opposing faces (Fa, Fb) of the support (21).