To provide a thermal insulation container the assembly of which is facilitated with a reduced number of composing members and the thermal insulation performance of which is improved.

This thermal insulation container comprises a rectangular thermal insulation floor panel 10, front and rear panels 21, 22, a pair of side panels 30, and a lid panel 40. The floor panel has protrusions 3 at the end surfaces of two opposing sides and also has packings 8 at the end surfaces of the two sides vertically crossing with them. The front and rear panels each have a recess 5A in the inner surface of the bottom side to be fitted to the protrusion of the floor panel, the two vertical sides vertically crossing with the recess have protrusion 3A and the end face of the top side end surface is provided with a protrusion 3B. The two side panels is provided with, on the inner surface of the bottom side, a packing 8A brought into close contact with the packing, and the two opposing vertical sides are each provided with a recess 5C that is slidingly fitted to the protrusion arranged at the vertical sides of the front and rear panels, and the end face of the top side is provided with a protrusion 3C. The lid panel is provided with, on the bottom surfaces of the four circumferential sides, recesses 5D to be fitted to the protrusions arranged at the end faces of the top sides of the front, rear and side panels.