PURPOSE: To provide the sealing device of a tubular bulb capable of sealing the tubular bulb with high reliability and capable of manufacturing a required fluorescent discharge lamp at a high yield.

CONSTITUTION: A sealing device is provided with a sealing head 10 having a bulb holding mechanism 10a holding a bulb 2 made of a glass fine tube and a mount holding mechanism 10b holding a mount 3 formed with an electrode member and a sealing burner 11 heating and softening the seal section 2a of the bulb 2 held by the bulb holding mechanism 10a from the outer periphery face to seal it to the inner mount 3. The sealing burner 11 is fitted to a moving body 15 circularly movably against the seal section 2a of the bulb 2, and a guide rod 18 is fitted and arranged on the moving body 15 in parallel with the sealing burner 11 so that the tip section can be brought into contact with the outer periphery face of the bulb 2.