A lighting device includes a heatsink 70, a socket 10 and an LED module 60. The LED module 60 has a light emitting unit 62 in a central part of a top side of a metal base substrate 63 composed of an insulating plate and a metal plate. The LED module 60 is warped such that the central part protrudes on a heatsink 70 side, which is the side opposite to the light emitting unit 62 side. The LED module 60 is mounted on the heatsink 70 in a state of the surrounds of the light emitting unit 62 being pressed according to pressing units 14T, 14L, and 14D of the socket 10. Pressing the surrounds of the light emitting unit 62 against the heatsink 70 ensures that a central part of the warping of the LED module 60 contacts the heatsink 70.