PURPOSE: To improve the using rate of a melt and to improve durability of a vessel for an evaporating source of an electron beam heating type by specifying the sectional shape of the containing part of said vessel.

CONSTITUTION: The side wall surface 3' in the containing part of a vessel for an evaporating source where a molten metal is held has a taper divergent toward the opening and the base 4' in the containing part is constituted of a curved surface projecting downward. Whether the curvature R thereof is single or plural is not a decisive factor and the preferable form is such that the tapered part is connected with the approximately smoothly curved surfaces from the terminal end thereof. The tapering angles β and γ of the surface 3' may be equal but are more preferably asymmetrical in the case of using the accelerated electron by an electron gun of a coaxial type.