Abstract: A hanging device facilitates the attachment of a foam board, or an equivalent object, to a wall. The hanging device has a body portion and at least one prong. The method of attaching the hanging device to the foam board includes the steps of inserting the prong upwardly into the foam board, and then rotating the body portion, which remains outside the foam board, so that at least part of the foam is compressed by the prong. If the foam board has a paper skin or backing, insertion of the prong creates a slot in the skin, and the slot tends to hold the device in position. The part of the body portion remaining outside the foam board can be suspended from a mounting device, such as a nail or a conventional picture hanger, affixed to a wall. The prong itself can also be bent towards the body portion, to increase the compression of the foam.