A loop heat pipe comprising: a pair of outermost metal layers (61, 66); an intermediate metal layer provided between the pair of outermost metal layers (61, 66); an evaporator configured to vaporize a working fluid to generate vapor; a condenser configured to liquefy the vapor of the working fluid; a liquid pipe connecting the evaporator and the condenser; and a vapor pipe connecting the evaporator and the condenser, and forming a loop shaped passage together with the liquid pipe, characterized in that: the intermediate metal layer includes a pair of walls forming a part of a pipe wall of the evaporator, the condenser, the liquid pipe, and the vapor pipe, a porous body provided between the pair of walls, a first strut penetrating the porous body and bonding the pair of outermost metal layers (61, 66) to each other, and one or a plurality of metal layers, wherein each of the one or plurality of metal layers of the intermediate metal layer includes a first part (621, 631, 641, 651) forming at least a part of the pair of walls, a second part (622, 632, 642, 652) connected to the first part (621, 631, 641, 651), and forming at least a part of the porous body, and a third part (623, 633, 643, 653) connected to the second part (622, 632, 642, 652), and forming at least a part of the first strut. a pair of outermost metal layers (61, 66); an intermediate metal layer provided between the pair of outermost metal layers (61, 66); an evaporator configured to vaporize a working fluid to generate vapor; a condenser configured to liquefy the vapor of the working fluid; a liquid pipe connecting the evaporator and the condenser; and a vapor pipe connecting the evaporator and the condenser, and forming a loop shaped passage together with the liquid pipe, characterized in that: the intermediate metal layer includes a pair of walls forming a part of a pipe wall of the evaporator, the condenser, the liquid pipe, and the vapor pipe, a porous body provided between the pair of walls, a first strut penetrating the porous body and bonding the pair of outermost metal layers (61, 66) to each other, and one or a plurality of metal layers, wherein each of the one or plurality of metal layers of the intermediate metal layer includes a first part (621, 631, 641, 651) forming at least a part of the pair of walls, a second part (622, 632, 642, 652) connected to the first part (621, 631, 641, 651), and forming at least a part of the porous body, and a third part (623, 633, 643, 653) connected to the second part (622, 632, 642, 652), and forming at least a part of the first strut. the intermediate metal layer includes a pair of walls forming a part of a pipe wall of the evaporator, the condenser, the liquid pipe, and the vapor pipe, a porous body provided between the pair of walls, a first strut penetrating the porous body and bonding the pair of outermost metal layers (61, 66) to each other, and one or a plurality of metal layers, a pair of walls forming a part of a pipe wall of the evaporator, the condenser, the liquid pipe, and the vapor pipe, a porous body provided between the pair of walls, a first strut penetrating the porous body and bonding the pair of outermost metal layers (61, 66) to each other, and one or a plurality of metal layers, wherein each of the one or plurality of metal layers of the intermediate metal layer includes a first part (621, 631, 641, 651) forming at least a part of the pair of walls, a second part (622, 632, 642, 652) connected to the first part (621, 631, 641, 651), and forming at least a part of the porous body, and a third part (623, 633, 643, 653) connected to the second part (622, 632, 642, 652), and forming at least a part of the first strut. a first part (621, 631, 641, 651) forming at least a part of the pair of walls, a second part (622, 632, 642, 652) connected to the first part (621, 631, 641, 651), and forming at least a part of the porous body, and a third part (623, 633, 643, 653) connected to the second part (622, 632, 642, 652), and forming at least a part of the first strut.