A substrate processing apparatus that includes a chamber, a substrate support disposed in the chamber, and a connection is provided. The chamber is provided with a bottom including a first flow path, and the substrate support includes a second flow path. The connection connects the first flow path to the second flow path, and the connection includes a sleeve through which the first flow path is in fluid communication with the second flow path, and a core including a first rod segment and a first elastic foam segment. The core is disposed in the sleeve, and a gap is defined between an inner surface of the sleeve and a side surface of the first rod segment.