PURPOSE: To smoothly flow a lubricant between a mold and molten steel shell and to improve the surface quality of a product by casting a mold by vibrating in the vertical direction by the nonsinusoidal waveform rapidly descending/slowly ascending.

CONSTITUTION: The vibration in the vertical direction of the nonsinusoidal waveform which is deformed waveform is obtd. by adjusting the intershaft distance C of driving shaft 8 and wave motion shaft 12. By vibrating a mold with the waveform like this, a lubricant is smoothly flowed between the mold and molten steel shell. By this method, the breakout due to a seizure can be prevented.