A method for manufacturing a boron-containing aluminum plate material comprises: a spreading step for spreading boron-containing alloy particles (3) in the shape of a layer over a bottom plate (2) placed in a container (1); a preheating step for preheating both the container (1) and a tundish (6) mounted on the container (1); a casting step for enveloped-casting the layer of the boron-containing alloy particles (3) in the container (1) with molten aluminum (10) by pouring the molten aluminum (10) into the tundish (6) to manufacture an enveloped-cast plate (14) with a predetermined thickness; and a cutting step for cutting off shrinkage cavities (13) occurring in a feeder section (12) of the upper portion of the enveloped-cast plate (14).