Shower plate

Patent Pending A compatible shower plate of constant quality in which a process gas blow-out hole has a simple structure and can be machined easily, the blow-out hole has dimensions of high precision and uneven blow-out of process gas and generation of particles are eliminated. Ceramic material-use power of low dielectric constant is press-formed into disc-shape having overall dimensions where sintering shrinkage and finish allowance are taken into account. In the stage of disc-like molding, a molding hole for a gas introduction passage (3) and the blow-out hole (2) is bored before sintering.