A loop heat pipe comprising: an evaporator configured to vaporize a working fluid; a condenser configured to condense the working fluid; a liquid pipe that connects the evaporator and the condenser to each other; a vapor pipe that connects the evaporator and the condenser to each other, and a loop-like flow channel (21, 22) that is provided in each of the evaporator, the condenser, the liquid pipe, and the vapor pipe, and through which the working fluid can flow, wherein at least one of the evaporator, the condenser, the liquid pipe and the vapor pipe comprises a first outer metal layer, a second outer metal layer, and an inner metal layer that is provided between the first outer metal layer and the second outer metal layer, and the inner metal layer comprises a porous body, wherein the porous body comprises a first bottomed hole formed in one face of the inner metal layer, a second bottomed hole formed in the other face of the inner metal layer, and a pore, wherein the first bottomed hole and the second bottomed hole partially communicates with each other through the pore, characterized in that the porous body further comprises a first convex portion provided inside the first bottomed hole, wherein the first convex portion has a proximal end connected to a bottom face of the first bottomed hole and a distal end provided on an opposite side to the proximal end in a thickness direction of the first convex portion, and the distal end of the first convex portion is provided at a position further recessed toward the bottom face of the first bottomed hole than the one face of the inner metal layer. an evaporator configured to vaporize a working fluid; a condenser configured to condense the working fluid; a liquid pipe that connects the evaporator and the condenser to each other; a vapor pipe that connects the evaporator and the condenser to each other, and a loop-like flow channel (21, 22) that is provided in each of the evaporator, the condenser, the liquid pipe, and the vapor pipe, and through which the working fluid can flow, wherein at least one of the evaporator, the condenser, the liquid pipe and the vapor pipe comprises a first outer metal layer, a second outer metal layer, and an inner metal layer that is provided between the first outer metal layer and the second outer metal layer, and the inner metal layer comprises a porous body, wherein the porous body comprises a first bottomed hole formed in one face of the inner metal layer, a second bottomed hole formed in the other face of the inner metal layer, and a pore, wherein the first bottomed hole and the second bottomed hole partially communicates with each other through the pore, characterized in that the porous body further comprises a first convex portion provided inside the first bottomed hole, wherein the first convex portion has a proximal end connected to a bottom face of the first bottomed hole and a distal end provided on an opposite side to the proximal end in a thickness direction of the first convex portion, and the distal end of the first convex portion is provided at a position further recessed toward the bottom face of the first bottomed hole than the one face of the inner metal layer.