To simplify work in mounting a packing mounting body to a heat insulating door, and to improve mounting strength.

A latching groove 33A is horizontally formed on a back face of a lower edge 38A of the heat insulating door 20. The L-shaped packing mounting body 51 constituted of a vertical section 52 opposed to the latching groove 33A of the back face of the heat insulating door 20 and a horizontal section 55 opposed to a lower face of the heat insulating door 20 is disposed, a mounting section 57 of a hanging packing 80 is formed on a lower face of the horizontal section 55 of the packing mounting body 51, on the other hand, a latching claw 54 latched in the latching groove 33A is disposed on an inner face of the vertical section 52. The packing mounting body 51 is mounted to a lower section of the heat insulating door 20 by latching the latching claw 54 of the vertical section 52 in the latching groove 33A, and fastening a mounting plate 65 disposed at an outer end of the horizontal section 55 with a screw 66.