PURPOSE: To improve waterproof property, working property, setting strength and design property of a corner construction by forming corner members in a lengthy shape containing a facing part composed of two facings with its section formed almost in a square, a recessed groove formed in a recessed shape near both ends of the facing part and an abutting surface having both ends of the facing part bent inward in an L shape.

CONSTITUTION: The bottom surface of a recessed groove 3 on a corner member A is made to abut on the top of a corner part on a dry type wall material D formed on a wall backing α composed of a steel frame backing of a C section, square section, H section, etc., or a timber structure backing of a space column, a main column, furring strips, etc., a water-proof sheet or the like, and the recessed groove 3 is fixed by a fixing means β such as a screw. An external angle part is formed by filling up the recessed groove 3 and a space between the facings of an abutting surface 4 and the dry type wall material D with a backup material B and a sealing material C. Thus waterproof property, airtight property, working property, setting strength and design property of a corner construction can be improved.