An insulation device for a low-temperature pipe , the insulation device comprising: a pair of primary insulation materials surrounding a first radially outer surface and a second radially outer surface of the pipe ; a pair of secondary insulation materials surrounding outer surfaces of the primary insulation materials ; a pair of tertiary insulation materials surrounding outer surfaces of the secondary insulation materials ; and a pair of finishing covers surrounding outer surfaces of the tertiary insulation materials , wherein the pair of secondary insulation materials are configured such that each of opposed contact surfaces thereof is formed in a shape bent at least one time, wherein a low-density foam insulation material is made of a foam material having a lower density than that of the secondary insulation materials , and covering each of lengthwise opposite ends of each of the secondary insulation materials and tertiary insulation materials , wherein each of the primary insulation materials is produced to have a shorter length than that of each of the secondary insulation materials , so that lengthwise opposite ends of the primary insulation material are located at positions inward from those of the secondary insulation material , and wherein a high-density foam insulation material is further provided, the high-density foam insulation material being in intimate contact with a lengthwise end of each of the primary insulation materials so as to cover a portion of the outer surfaces of the pipe that is not covered by the primary insulation material , and having a side protruding farther than an outer surface of the low-density foam insulation material . a pair of primary insulation materials surrounding a first radially outer surface and a second radially outer surface of the pipe ; a pair of secondary insulation materials surrounding outer surfaces of the primary insulation materials ; a pair of tertiary insulation materials surrounding outer surfaces of the secondary insulation materials ; and a pair of finishing covers surrounding outer surfaces of the tertiary insulation materials , wherein the pair of secondary insulation materials are configured such that each of opposed contact surfaces thereof is formed in a shape bent at least one time, wherein a low-density foam insulation material is made of a foam material having a lower density than that of the secondary insulation materials , and covering each of lengthwise opposite ends of each of the secondary insulation materials and tertiary insulation materials , wherein each of the primary insulation materials is produced to have a shorter length than that of each of the secondary insulation materials , so that lengthwise opposite ends of the primary insulation material are located at positions inward from those of the secondary insulation material , and wherein a high-density foam insulation material is further provided, the high-density foam insulation material being in intimate contact with a lengthwise end of each of the primary insulation materials so as to cover a portion of the outer surfaces of the pipe that is not covered by the primary insulation material , and having a side protruding farther than an outer surface of the low-density foam insulation material . <EOS>