An autoclavable electrical switch assembly for use with a medical device having electrical functions comprising a flexible substrate formed of an insulating material and having a first and second surfaces, and having outer margins, first conductive means adherent to the first surface and forming a pattern surrounding an area of the surface and a contact disposed within the area, second conductive means adherent to the second surface and forming a ground plane and at least one, feedthrough means forming a connection between the contact on the first surface and the ground plane on the second surface, a snap dome of a conductive material overlies the contact and engages the pattern surrounding the area, flexible cover means disposed over the first and second surfaces and means for forming a hermetic seal between the outer margins so that the dome is hermetically sealed, said cover means and said hermetic seal being capable of withstanding repeated autoclaving.