A loop heat pipe comprising: an evaporator configured to vaporize a working fluid (C); a condenser configured to condense the working fluid (C); 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 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 (C); a condenser configured to condense the working fluid (C); 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 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 . <EOS>