To provide a storage device which is added into an existing wall cabinet for easily and safely moving articles into and out of the wall cabinet which is too high for the aged and children.

A storage element, which makes parallel movement from the high wall cabinet to a position where it is easy to perform the operation of moving articles in and out, is attached to the existing wall cabinet by an adding means. As the adding means, sandwiching portions provided at the lower portions of a pair of right and left mounting bases to which the storage element is connected by a link mechanism are used to sandwich the bottom plate of the wall cabinet to fix the storage device in place.