The invention provides an interfacial process for continuous production of polycarbonate resin which is so improved as to give high-quality polycarbonate stably. In producing a polycarbonate resin continuously by interfacial polycondensation of an aqueous alkaline solution of a dihydroxyl compound with carbonyl chloride, a manufacturing plant is used which comprises as the essentials a raw material preparation tank, an oligomerization tank, a polycondensation tank, a washing tank, a resin isolation tank which are connected in series and provided respectively with vent lines, with at least twoof the vent lines being independently connected to an exhaust gas treatment unit.