A cell for use in electrochemical mass spectrometry (EMS) using silicon rubber membranes and a gold substrate is described. The silicon rubber membrane used has a time constant and sensitivity for small molecules comparable with that of the microporous PTFE membranes used traditionally, but eliminates the need for a special prevacuum chamber and extra turbomolecular pump in the mass spectrometer. To investigate porous electrode materials a microporous electronically conducting film is formed on the silicon rubber membrane by evaporation. Below the potential of oxide formation the gold film behaves as an electrochemically inert substrate for the oxidation of methanol on different porous electrode materials. The applicability of the set-up has been demonstrated by mass spectrometric cyclic voltammetry (MSCV) on the oxidation of methanol on platinum black.