In a foil sealed lamp, a lamp container made of transparent material, has at least one sealing portion made of molybdenum wherein a metallic foil is buried, a light emitting section which is connected to one end of the metallic foil and a lead rod extending outward and connected to other end of the metallic foil, and wherein, in the sealing portion, a gap formed around a circumference portion of the lead rod is filled with sealing agent made of rubidium oxide or cesium oxide, and glass having boron oxide and bismuth oxide as principal components is coated on an outer end surface of the sealing portion so as to close the gap.