A fluorescent lamp has an amalgam chamber that is in communication with the interior of the lamp through an exhaust tube. The amalgam chamber is constructed as a three-way junction with the exhaust tube and is formed at a supplementary angle of 180 degree or less with respect to the exhaust tube. The construction of the chamber utilizes the force of gravity to keep the amalgam away from the opening of the exhaust tube leading to the interior of the lamp. The amalgam chamber is capable of effectively retaining the amalgam within the chamber and preventing it from penetrating into the interior of the lamp regardless of mounting direction.