A probe card of a testing apparatus of electronic devices comprises a testing head, which houses a plurality of contact elements extending along a longitudinal axis between a first end portion and a second end portion, a support plate, onto which the first end portion is adapted to abut, and a flexible membrane. Suitably, the testing head is arranged between the support plate and a first portion of the flexible membrane, which is connected to the support plate through a second portion thereof, the probe card further comprising a plurality of contact tips arranged on a first face of the flexible membrane at the first portion thereof, the second end portion of each contact element being apt to abut onto a second face of the flexible membrane, opposite to the first face, the number and distribution of the contact elements being different to the number and distribution of the contact tips.