Abstract: The invention concerns the structure of the sample support plates for mass spectrometric analysis of organic samples ionized by matrix-assisted laser desorption. The invention consists of a highly flat plate, electrically conductive at least on its surface, rigidly bonded to a base structure in such a way that together they form a body having the external dimensions of a microtitre plate, but such that thermal distortions of the surface cannot occur. The base structure may have both depressions for frictional gripping by a robot as well as a machine-readable identifier.