An LED lamp includes a plurality of LED modules arranged in direction x, a tubular enclosure for housing the LED modules that is open at ends spaced from each other in direction x, and end caps respectively closing the ends of the tubular enclosure in direction x. Each of the end caps is configured to diffuse light from the LED modules while transmitting the light, and includes an emission surface for emitting light in a direction z perpendicular to direction x. This arrangement ensures that the LED lamp has a good appearance even when it is made long.