A valve apparatus includes a first base block having flow passages formed therein, a second base block and a control block. By connecting together side surfaces of the blocks so that the surfaces mutually oppose one another, a manifold formed in the interior of each of the blocks is configured and connected, and valves are installed internally in the first base block and the second base block. Further, gaskets are gripped between each of the interconnected parts, wherein the gaskets are held in a state of being flush with or protruding with respect to outer surfaces of the blocks that are positioned on both sides of the gaskets.