To provide a heat insulating wall structure for a building, which has no cavity between a packing and a urethane heat insulating layer, and improves the heat insulation properties of the packing per se.

According to the heat insulating wall structure, the heat insulating packings 3 are connected to an inner wall surface 2 of a concrete wall 1 at necessary locations. Each heat insulating packing is formed like a rod or a block, which is produced by crushing waste of rigid urethane foam to obtain a number of urethane granules 4, and then bonding the urethane granules to each other by a binder 5. Further a rigid polyurethane foam material 7 is sprayed onto the other area of the inner wall surface 2 so as to cover both side surfaces and a top surface of the heat insulating packings 3, as well, to thereby form the urethane heat insulating layer 8 adhering to the inner surface. The urethane heat insulating layer 8 is further covered with an additional inner wall 9 facing to the inner wall surface of the concrete wall 1, and the additional inner wall 9 is fixed to the heat insulating packings 3 by nails, screws, or the like.