To apply appropriate and efficient mercury removal to crushed glass grain pieces when a fluorescent vessel is cleaned by discharging the fluorescent film and mercury from a glass pipe of the fluorescent vessel, thereafter, crushing the glass pipe and applying removal treatment of remaining mercury to the thus obtained crushed glass grain pieces.

Compression gas is blown to an inner surface of the glass pipe of the fluorescent vessel 1 cut/removed with a base part from one end to the other end or a grinding material is blown with the compression gas and the fluorescent film coated on an inner surface of the glass pipe and the mercury filled in the glass pipe are discharged from the glass pipe. Then, the glass pipe 6 is cut to at least three parts of two end parts and one central part and the glass pipe is sorted to the end parts 8 and the central part 9 to recover them.