PURPOSE: To supply automatically molten metal with accurate rate by selecting a shape of ladle as becoming the constant surface area of the molten metal at any tilting angle of the ladle at the time of pouring the molten metal by tilting the ladle.

CONSTITUTION: The ladle 14 is composed in parallel to the both sides and the inner face 15d if formed as radial section, as becoming always the constant surface area P of a virtual horizontal face, which connects the inner face 15D with the edge part of the opening 15c, in the range of the tilting angle θ1Wθ2. Further, a memory means, which stores a functional equation composing of the tilting angle θ of the ladle 14 and molten metal weight introduced in the ladle 14 is arranged as combining in this ladle 14. Thus, at the time of introducing the molten metal into the ladle 14 in a crucible, the tilting angle θ, corresponding to the desired molten metal weight is calculated through the above- mentioned memory means, and the ladle 14 is tilted automatically. In this way, the accurate weight of the molten metal is supplied automatically by the ladle.