To provide a connection structure of heat insulating panels eliminating work on a gondola and a scaffolding to allow safe and easy installation of the heat insulating panels to ensure waterproofness of connection parts of the heat insulating panels.

In the connection structure of the heat insulating panels A formed by filling a heat insulating material 3 between two metal skins 1, 2, a joint piece 4 is projected to the side from the side end of each heat insulating panel A. The adjacent heat insulating panels A, A are disposed with the joint pieces 4 facing each other, and a joint 5 is formed by the facing joint pieces 4, 4. Waterproof members 6 are provided in the joint 5, and the joint 5 is provided with an opening communicating with an outdoor side space rather than the waterproof members 6. A gutter member 7 is disposed on the indoor side of the joint 5, and an airtight member 8 is provided between the joint piece 4 and the gutter member 7. A space between the waterproof members 6 and the gutter member 7 is formed as an isobaric space 9 equal in atmospheric pressure to the outdoor side space.