To supply a casting building material having a spike or a catching hook at a low cost.

In the method for manufacturing the building material 1, a mold 4 composed of an upper sand mold 41 and a lower sand mold 42 is used, head parts 31 (one end side 310) of nails 3 (metallic wire rod 30) are arranged inside a casting space 43 in the mold 4, the shaft parts 32 (the other end side 320) of the nails 3 (metallic wire rods 30) are stuck into the upper sand mold 41 or the lower sand mold 42, and the building material body 2 is cast by pouring the molten metal into the inner part of the casting space 43, then the shaft parts 32 (the other end side 320) of the nails 3 (metallic wire rods 30) protruded from the building material body 2 are used as the spike or the catching hook.