An LED lighting device comprising: a light emitting unit comprising an LED; a lighting unit which turns on the LED and comprises a lighting circuit component (12a, 12b); and a device main body having the light emitting unit and the lighting unit housed inside the device main body; wherein the device main body comprising a main body portion which comprises an opening on one end side and comprises a wall portion on the other end side that is opposite to the opening side with an insertion portion formed at a central part of the wall portion, a protruding portion which protrudes from the wall portion having space with an inside of the protruding portion continuing into the insertion portion and the main body portion, and a heat conducting portion (4, 22) attached to the other end side of the protruding portion in such a way as to face the insertion portion and with one end side thereof protruding from the wall portion toward the opening and with the other end side thereof attached to the other side of the protruding portion in a way to face the insertion portion that enables heat conduction, wherein the light emitting unit is connected to the one end side of the heat conducting portion (4, 22) in a way that enables heat conduction, and at least a portion of the lighting circuit component is arranged inside the space of the protruding portion; wherein the lighting unit comprises a circuit board on which the lighting circuit component (12a, 12b) is mounted, and the circuit board is arranged toward the opening from the wall portion in a way to face the wall portion and the lighting circuit component is mounted on a surface on the side of the wall portion of the circuit board; and the light emitting unit configured as a part of the circuit board comprises the LED mounted on a surface on one end side of the circuit board and with a surface on the other end side of the circuit board connected to the heat conducting portion (4, 22) in a way that enables heat conduction. a light emitting unit comprising an LED; a lighting unit which turns on the LED and comprises a lighting circuit component (12a, 12b); and a device main body having the light emitting unit and the lighting unit housed inside the device main body; wherein the device main body comprising a main body portion which comprises an opening on one end side and comprises a wall portion on the other end side that is opposite to the opening side with an insertion portion formed at a central part of the wall portion, a protruding portion which protrudes from the wall portion having space with an inside of the protruding portion continuing into the insertion portion and the main body portion, and a heat conducting portion (4, 22) attached to the other end side of the protruding portion in such a way as to face the insertion portion and with one end side thereof protruding from the wall portion toward the opening and with the other end side thereof attached to the other side of the protruding portion in a way to face the insertion portion that enables heat conduction, wherein the light emitting unit is connected to the one end side of the heat conducting portion (4, 22) in a way that enables heat conduction, and at least a portion of the lighting circuit component is arranged inside the space of the protruding portion; wherein the lighting unit comprises a circuit board on which the lighting circuit component (12a, 12b) is mounted, and the circuit board is arranged toward the opening from the wall portion in a way to face the wall portion and the lighting circuit component is mounted on a surface on the side of the wall portion of the circuit board; and the light emitting unit configured as a part of the circuit board comprises the LED mounted on a surface on one end side of the circuit board and with a surface on the other end side of the circuit board connected to the heat conducting portion (4, 22) in a way that enables heat conduction.