Branched polycarbonate production method

A branched polycarbonate production method comprising a step (a) for obtaining a reaction solution by causing a phosgene reaction among a dihydric phenol alkali aqueous solution, phosgene, and a branching agent in the presence of an organic solvent, a step (b) for obtaining a reaction solution including a polycarbonate oligomer by adding a dihydric phenol alkali aqueous solution and a polymerization catalyst to the reaction solution obtained at step (a), a step (c) for separating the reaction solution including a polycarbonate oligomer obtained at step (b) into a water phase and an organic solvent phase including a polycarbonate oligomer, and a step (d) for obtaining a reaction solution including a branched polycarbonate by reacting a dihydric phenol alkali aqueous solution with the organic solvent phase including a polycarbonate oligomer separated at step (c), wherein (x/y) is equal to or greater than 0.0035, where the polymerization catalyst content added at step (b) is x mol/hr and the chloroformate group content of the polycarbonate oligomer included in the reaction solution obtained at step (b) is y mol/hr.