NOVELTY - The substrate holding device comprises a first holding member (102) comprising a support surface (102a) for placing an edge portion of a substrate (112) and an opening in its inner area, a second holding member (106), which is releasably connected to the first holding member such that the support surface is provided between the members, a space to receive the substrate, and a connection structure for releasably connecting the holding members. The support surface defines the opening or completely surrounds the opening, and is arranged within the space.    USE - The substrate holding device is useful in a process chamber such as a vacuum chamber (all claimed), where the substrate is a polymer film, a sheet, a metal foil or a bipolar plate and is useful for a fuel cell.    ADVANTAGE - The substrate holding device has improved flexibility.    DETAILED DESCRIPTION - The substrate holding device comprises a first holding member (102) comprising a support surface (102a) for placing an edge portion of a substrate (112) and an opening in its inner area, a second holding member (106), which is releasably connected to the first holding member such that the support surface is provided between the members, a space to receive the substrate, and a connection structure for releasably connecting the holding members. The support surface defines the opening or completely surrounds the opening, and is arranged within the space. A hold-down clamp member (108): is arranged between the members relative to the support surface; is attached to the second holding member or integrally formed with the second holding member; and has a spring element. A force is exerted on the hold-down clamp member. The connection structure comprises pins, which laterally secure the first holding member to the second holding member. The second holding member has a through hole for receiving the connection structure. The hold-down clamp member comprises carbon, preferably carbon fiber-reinforced carbon, metal, plastic, synthetic fabric and rubber. The holding members are formed of same material.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a substrate holding device.    First holding member (102)    Support surface (102a)    Second holding member (106)    Hold-down clamp member (108)    Substrate. (112)