Abstract: A securing device for rear walls set in grooves of cabinet furniture exhibits at least one support element that can be placed in the angle area between the rear wall and a grooved sidewall and at least one other support element that can be placed in the angle area between the rear wall and a grooved shelf and/or top board. The support elements (10) exhibit contact sides that are each at a right angle to one another and diagonal to these contact sides a throughhole (12) for receiving a setscrew or a set pin. For purposes of easier handling and more reliable securing of the cabinet furniture elements, which are to be connected to one another in the corner area at an angle of 90 degrees, the at least two support elements (10) are integrated in one piece into the two legs (2) of a corner angle piece. At least one of the support elements (10) is formed at each of the legs (2) of the corner angle piece.