NOVELTY - The casting mold (100) has casting mold main portion (1) provided with bottomed cylindrical shape opening portion (11) for supplying molten metal of copper-gallium alloy. A guide portion (100A) is used to decrease kinetic energy of molten metal of copper-gallium alloy, and is used to guide and pour molten metal supplied towards opening portion provided in casting mold main portion. The molten metal is flowed along inclined surface (21) of inclination element (2) formed between internal peripheral surfaces of casting mold main portion.    USE - Casting mold for manufacture of copper-gallium alloy slab of sputtering target (all claimed) for formation of thin-film solar cell.    ADVANTAGE - The molten metal is uniformly solidified, such that the casting mold can suppress generation of the crack at time of manufacturing the copper-gallium alloy slab. The large sized copper-gallium alloy slab is easily manufactured by using the casting mold. The gap is formed in the inclined surface of the inclination element, such that the molten metal of copper-gallium alloy is easily poured in the casting mold main portion. Since the length of the inclined surface of the inclination element is fully securable, the controllability of the flow-by rate of the molten metal flowed along the inclined surface can be improved, to improve the controllability regarding the reduction of the kinetic energy of the molten metal poured in the casting mold main portion. The guide portion is used to decrease kinetic energy of the molten metal, and is used to guide and pour the molten metal supplied towards opening portion provided in casting mold main portion.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a copper-gallium alloy slab;    (2) a sputtering target; and    (3) a method for manufacturing the copper-gallium alloy slab.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the structure of the casting mold.    Casting mold main portion (1)    Inclination element (2)    Opening portion (11)    Inclined surface (21)    Casting mold (100)    Guide portion (100A)