An emergency exit indicator includes a flat housing and a light source received in the housing. The housing has a length greater than a width thereof. The housing includes a panel provided with a sign thereon to indicate emergency exit. The light source includes a plurality of LEDs each being covered by a lens. Light of the LED goes through the lens and is then illuminated on the sign to cause the sign to be visible. The lens has two opposite sides along a lengthwise direction of the housing longer than other two opposite sides along a widthwise direction of the housing, such that the light through the lens along the widthwise direction of the housing is converged in a narrower manner than the light through the lens along the lengthwise direction of the housing.