To provide an external wall construction building material capable of simply providing furring strips (venting space formation material) for ensuring a venting space in comparison with the past and simplifying the construction of an external wall having a structure promoting durability of a building by controlling the occurrence of condensation.

The external wall construction building material 10 is constituted of a waterproofed paper 12 having a predetermined size, the venting space formation material 14 fixed to one side of the waterproofed paper 12 and a lath net 16 fixed to the other side of the waterproofed paper 12, and the venting space is formed between a substrate and the lath net 16.