To provide a method for producing an outside angle member for an external finish wall material molded into an L-shape, which prevents an adhesive overflowing the outside of an L-shaped corner portion from flowing on a surface of the outside angle member when both abutting end faces of the outer corner member are bonded together, to thereby dispense with removing work of the overflowing adhesive in the following steps.

Using the method, a plate body 2 of an arbitrary size is cut away from a rectangular wall plate 1, and diagonal portions 21 which can form an angle with respect to each other when abutted, corresponding to a corner angle of a mounting target, are formed on a cut end face of the plate body 2, while a vertical portion 22 is left on the side of a front surface of the plate body 2. Thus, the two diagonal members are bonded together, to obtain the L-shaped outside angle member, and then a chamfered portion 7 is formed on the outside of the L-shaped corner portion.