PURPOSE: To reduce temperature difference between the upper area and the lower area of an emission tube by providing the upper area of the inner surface of an outer encircling case with a part on which a metal is vapordeposited and a reflecting mirror part on which no vapordeposition is performed and horizontally installing the emission tube in such a manner as to locate it apart from the center line of the outer encircling tube.

CONSTITUTION: The upper area of the inner surface of an outer encircling tube 1 made of hard glass or the like has a part 1-1 on which a metal is vapordeposited and a reflecting mirror part 1-2 which has a width of X and a length of Y and on which no vapordeposition is performed. An emission tube 3 is installed inside the outer encircling tube 1 in such a manner as to locate the center line (b) of the emission tube 3 apart from the center line (a) of the outer encircling tube 1 by not more than 20mm toward the reflecting mirror part 1-2 thereby constituting an electric-discharge lamp for luring fish. This lamp is used in the horizontal position. As result, temperature difference between the upper side and the lower side of the emission tube 3 is reduced by increasing the temperature of the lower side of the emission tube 3 through reflected heat without causing any reduction in the intensity of light directed obliquely downward. Besides, the maximum temperature of the internal area of the outer encircling tube 1 can be decreased, thereby enabling the life of the lamp to be extended.