To provide a corner wall face material having improved strength and durability with easy manufacturing work, and to provide its manufacturing method.

In manufacturing the corner wall face material 1, two plate materials 2, 3 each of which has one side end face cut at a predetermined angle for adhesive A to be applied thereto are put into the condition of abutting on each other and then they are heated and adhered to each other with high frequency induction heating. Part A1 of the adhesive A applied to abutment faces 2a, 3a of an abutment portion 4 stick out a V-grooved portion 5 which is formed in the abutment portion 4 between the two plate materials 2, 3, along the longitudinal direction of the V-grooved portion 5. The stick out adhesive A1 is adhered to the two plate materials 2, 3 with high frequency induction heating.