A carbon membrane structure includes: a cylindrical porous support body provided with a plurality of cells extending from one end face to the other end face and functioning as fluid passages, and a carbon membrane disposed on the surface side of the cells formed in the porous support body. The plurality of cells are formed so that a distance from one cell to another cell adjacent to the one cell in a cross section perpendicular to a cell extension direction of the porous support body 1 is 0.60 mm or more. The carbon membrane structure shows very excellent separation performance by the carbon membrane.