Support apparatus (1) for equipment for lying or sitting on, having an at least partially fixed frame (2) and having intertwined, tension straps (4), which define a support surface (8) and are accessible both from the upper, support side and from the opposite underside of the support surface (8), wherein at least some of the straps (4) are connected to the frame (2) by means of separately adjustable tensioning devices (7), in which case the tensioning of the straps (4) is locally adjustable and therefore the hardness of the support surface (8) is locally adaptable at any time.