A gasket type orifice includes a first orifice base having a through-type passage in a central area thereof, a second orifice base having in a central area thereof a through-type passage communicating with the passage of the first orifice base, and an orifice plate having an orifice hole formed in a central area thereof, wherein the orifice plate is mounted by insertion in an airtight manner between both orifice bases, and the gasket type orifice is installed in a fluid passage, in which the outer end faces of both orifice bases respectively serve as sealing faces, and an outer diameter of the second orifice base, located on the downstream side, is larger than an outer diameter of the first orifice base located on the upstream side, and an outer peripheral edge portion of an inner end face of the second orifice base serves as another sealing face.