A sliding gate valve includes a valve body (1) and a valve plate (5) which can slide transversely to the direction (108) of flow of the medium and exhibits narrow slot passages (50, 51) running transversely to the direction of the stroke, and which cooperates with a counterpart (4). The counterpart (4) is composed of a valve seat (40) which, like valve plate (5), consists completely of ceramic, and further includes a metallic supporting part (41) which supports the valve seat (40) across the whole area of the side of it opposite valve plate (5). The counterpart (4) includes passages which may be opened or closed by the valve plate (5) and are formed by slotted passages (400, 410; 401, 411; 402, 412)in alignment in the valve seat (4) and in supporting part (41). The valve plate (5) is connected via a screw connection (6, 61, 610; 8, 61, 615) to a driving unit which includes a part (33) acted upon by a control medium. This driving unit is, in turn, connected via a connecting part (2) to the valve body (1). Screw connection (6, 61, 610; 8, 61, 615) adjusts the distance between part (33) and valve plate (5) and allows precise alignment of the passages of the valve plate (5) and valve seat (40) which is critical owing to the brittleness of the ceramic material.