A method and apparatus for continuous casting of an elongated thin metal strip achieves substantially high yield without allowing break-out or sticking. The method for casting a continuous elongated metal strip according to the present invention includes a step of driving endless belts at a varying speed so as to apply jerks to the slightly and half-solidified metal that release the metal from the surfaces of the stationary side walls. Applying jerks to the casting chamber by varying the driving speed of the endless belt ensures that the solidifying metal will travel smoothly and thus ensures a high manufacturing yield.