TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The support element is plastically deformable, and comprises a bead. The support element forms part of a first component of the electrochemical device, and the sealing element is arranged between the first component and a second component of the electrochemical device in the assembled condition of the electrochemical device. The sealing element is fixed to the first component and / or on the second component of the electrochemical device. The sealing element is at least partially arranged on a region of the supporting elements, which protrude toward the second component; or the sealing element is at least partially arranged on a region of the supporting elements, which projects to a side remote from the second component towards the first component. The second component comprises a projection projecting towards the sealing element. The electrochemical device comprises a stacking (102) of several electrochemical units (106) arranged sequentially along a stacking direction, and a clamping device comprises a clamping force directed with a longitudinal direction of the stacking for applying to the electrochemical units. The support element and/or the sealing element, in a first region of the electrochemical device in which the clamping force is greater than in a second region of the electrochemical device, comprises a greater width than in the second region of the electrochemical device. The support element and/or the sealing element, in a first region of the electrochemical device in which the clamping force is greater than in a second region of the electrochemical device, has a lower height than in the second region of the electrochemical device. The electrochemical device comprises at least one media channel, which extends along a stacking direction by several electrochemical units of the electrochemical device, arranged sequentially along a stacking direction, a flow field through which a fluid medium from the medium channel cross to the stacking direction, flows to another medium channel, and includes at least one connecting channel through which the flow field and the media channel is present in fluid communication with each other. The sealing assembly comprises a flow field-portion, which passes between the medium channel and the flow field and crosses the connecting channel. The flow field-portion includes a connecting channel area, in which the flow field-portion traverses to at least one connecting duct, and at least one neighboring region lying in the longitudinal direction of the flow field portion before or after the connecting channel area, and the sealing element, in the assembled state of the sealing assembly in the connecting channel area, has a lower height than in the neighboring region. The sealing assembly comprises a media channel-portion, which at least partially surrounds the media channel, and the sealing element, in the assembled state of the sealing assembly in the medium channel-portion, has a greater height than in the connecting channel area of the flow field-portion. The support element of the sealing assembly has at least one through-opening, through which a connecting channel extends.