To provide a corner covering wall member for covering an intersecting portion of a parting wall member to a side having a smaller angle created by two parting members intersecting each other at an L-shaped intersecting portion between a parting member covering an end portion by a building panel and another parting member intersecting the parting member at a right angle to the parting member where the member intersects, at a right angle, the parting member covering its end portion with a wall panel.

An almost flat L-shaped corner surface is made by forming sheet metal for corner covering; a hook piece is formed to a semicircular shape by bending an inner side end having an angle of 90 degrees to its rear surface side at its inner side end of the corner surface having an L-shape; a push lock piece is formed at an outer side end at the L-shaped corner having an angle of 270 degrees; linking projections and linking grooves are formed at a parting side where the parting members are covered by a building panel at their end and also, during construction work, at a side outside of the building panel of the parting side; and the hook piece of the corner covering is caught by a tip of the parting side, and the push-lock piece of the corner covering gets over the linking projections of the parting members and enters the linking grooves.