NOVELTY - The cell has a peripheral frame seal (3) provided in a contact region of both anode and cathode half-shells (14, 15) between frame-like flange regions (16, 17) of outer walls (12, 13) of the half-shells. The seal rests on a membrane (8). The seal overlaps a porous medium (9) and a gas diffusion electrode (6). The medium and the electrode lie on one of the flange regions (17). The seal includes a profile in the contact region outside an inner profiled region of the medium and the electrode. The profile and/or a deformable sealing cord is arranged in an inner region (23) of the cell.    USE - Electrochemical cell for use as an electrolysis cell in an electrolyzer, a battery and a fuel cell for converting chemical energy into electrical energy (all claimed).    ADVANTAGE - The peripheral frame seal includes the profile in the contact region outside the inner profiled region of the medium and the gas diffusion electrode, thus providing sufficient sealing of a gas space against an electrolyte space. The cell prevents arrival of electrolyte over insufficiently sealed regions i.e. perpendicular edge regions between the gas diffusion electrode, the porous medium and the sealing cord, for an electrolytic process, and permits the regions to be unavailable for electrochemical region. The cell allows simple insertion and removal of the electrode, provides a small inactive sealing surface, and provides a very large active electrode surface for using an electrochemical reaction. The cell ensures electrical insulation of the anode from the cathode for achieving intended functionality of the cell.    DETAILED DESCRIPTION - The peripheral frame seal is made of lye and oxygen resistant material.    DESCRIPTION OF DRAWING(S) - The drawing shows a top sectional view of an electrochemical cell.    Peripheral frame seal (3)    Gas diffusion electrode (6)    Membrane (8)    Porous medium (9)    Outer walls (12, 13)    Anode half-shell (14)    Cathode half-shell (15)    Frame-like flange regions (16, 17)    Inner region of electrochemical cell (23)