An LED lamp has a convex lens 3 which has an upper portion 5 and a lower
portion 6. An upper curved surface 5A of the upper portion is different
in shape from a lower curved surface 6A of the lower portion 6 so as to
refract rays of light from an LED chip 2 more strongly than the lower
curved surface 6A does. This avoids reflection of incident outside light
toward a front and hence prevents misrecognition. An interface plane S1
between the upper and lower portions 5 and 6 of the convex lens 3 is
located on an upper end face 2A to thereby prevent collection of outgoing
light upon the interface plane S1 and generation of an irregular emission
peak at the front.