A loop heat pipe comprising: an evaporator that vaporizes a working fluid; a condenser that liquefies the working fluid; a liquid pipe that connects the evaporator and the condenser; a vapor pipe that connects the evaporator and the condenser, to form a loop-shaped passage together with the liquid pipe; and a porous body (60, 60A, 70, 70A) provided inside the the evaporator, and formed by forming bottomed holes in a first metal layer (62, 72), wherein the bottomed holes of the first metal layer (62, 72) include a first bottomed hole (62x, 72x) that caves in from a first surface of the first metal layer, and a second bottomed hole (62y, 72y) that caves in from a second surface of the first metal layer, opposite to the first surface, and wherein a bottom surface of the first bottomed hole (62x, 72x) and a bottom surface of the second bottomed hole (62y, 72y) are alternately aligned and adjacent to each other and partially overlap each other so that the first bottomed hole (62x, 72x) and the second bottomed hole (62y, 72y) partially communicate with each other to form a pore (62z, 72z) wherein the porous body (60, 60A, 70, 70A) includes a connecting part provided on a side where the liquid pipe connects to the evaporator, one or a plurality of protruding parts (60w, 60k) protruding from the connecting part toward the vapor pipe, and a space formed inside the evaporator in a region where the porous body (60, 60A, 70, 70A) is not provided and communicating to a flow passage of the vapor pipe. an evaporator that vaporizes a working fluid; a condenser that liquefies the working fluid; a liquid pipe that connects the evaporator and the condenser; a vapor pipe that connects the evaporator and the condenser, to form a loop-shaped passage together with the liquid pipe; and a porous body (60, 60A, 70, 70A) provided inside the the evaporator, and formed by forming bottomed holes in a first metal layer (62, 72), wherein the bottomed holes of the first metal layer (62, 72) include a first bottomed hole (62x, 72x) that caves in from a first surface of the first metal layer, and a second bottomed hole (62y, 72y) that caves in from a second surface of the first metal layer, opposite to the first surface, and a first bottomed hole (62x, 72x) that caves in from a first surface of the first metal layer, and a second bottomed hole (62y, 72y) that caves in from a second surface of the first metal layer, opposite to the first surface, and wherein a bottom surface of the first bottomed hole (62x, 72x) and a bottom surface of the second bottomed hole (62y, 72y) are alternately aligned and adjacent to each other and partially overlap each other so that the first bottomed hole (62x, 72x) and the second bottomed hole (62y, 72y) partially communicate with each other to form a pore (62z, 72z) wherein the porous body (60, 60A, 70, 70A) includes a connecting part provided on a side where the liquid pipe connects to the evaporator, one or a plurality of protruding parts (60w, 60k) protruding from the connecting part toward the vapor pipe, and a space formed inside the evaporator in a region where the porous body (60, 60A, 70, 70A) is not provided and communicating to a flow passage of the vapor pipe.