A horizontal type cylindrical double-shell tank comprising: an inner shell including an inner shell main part storing a liquefied gas and an inner shell dome protruding in a particular direction from the inner shell main part; an outer shell including an outer shell main part surrounding the inner shell main part and an outer shell dome surrounding the inner shell dome; and a pipe; the horizontal type cylindrical double-shell tank being characterised in that it further comprises: a deformable member deformable in the particular direction and incorporated in the outer shell dome so as to divide the outer shell dome into a fixed part located at a base side with respect to the deformable member and a movable part located at a distal end side with respect to the deformable member; a first restricting mechanism disposed between the movable part of the outer shell dome and the inner shell dome, the first restricting mechanism restricting movement of the movable part of the outer shell dome and movement of the inner shell dome relative to each other in the particular direction while allowing the inner shell dome to contract; a second restricting mechanism disposed between the fixed part of the outer shell dome and the inner shell dome, the second restricting mechanism restricting movement of the inner shell dome in a radial direction while allowing the inner shell dome to contract and allowing the inner shell dome to move in the particular direction relative to the fixed part; and in that the pipe penetrates the movable part of the outer shell dome and the inner shell dome. an inner shell including an inner shell main part storing a liquefied gas and an inner shell dome protruding in a particular direction from the inner shell main part; an outer shell including an outer shell main part surrounding the inner shell main part and an outer shell dome surrounding the inner shell dome; and a pipe; the horizontal type cylindrical double-shell tank being characterised in that it further comprises: a deformable member deformable in the particular direction and incorporated in the outer shell dome so as to divide the outer shell dome into a fixed part located at a base side with respect to the deformable member and a movable part located at a distal end side with respect to the deformable member; a first restricting mechanism disposed between the movable part of the outer shell dome and the inner shell dome, the first restricting mechanism restricting movement of the movable part of the outer shell dome and movement of the inner shell dome relative to each other in the particular direction while allowing the inner shell dome to contract; a second restricting mechanism disposed between the fixed part of the outer shell dome and the inner shell dome, the second restricting mechanism restricting movement of the inner shell dome in a radial direction while allowing the inner shell dome to contract and allowing the inner shell dome to move in the particular direction relative to the fixed part; and in that the pipe penetrates the movable part of the outer shell dome and the inner shell dome. a deformable member deformable in the particular direction and incorporated in the outer shell dome so as to divide the outer shell dome into a fixed part located at a base side with respect to the deformable member and a movable part located at a distal end side with respect to the deformable member; a first restricting mechanism disposed between the movable part of the outer shell dome and the inner shell dome, the first restricting mechanism restricting movement of the movable part of the outer shell dome and movement of the inner shell dome relative to each other in the particular direction while allowing the inner shell dome to contract; a second restricting mechanism disposed between the fixed part of the outer shell dome and the inner shell dome, the second restricting mechanism restricting movement of the inner shell dome in a radial direction while allowing the inner shell dome to contract and allowing the inner shell dome to move in the particular direction relative to the fixed part; and in that the pipe penetrates the movable part of the outer shell dome and the inner shell dome.