To provide a mercury purifying apparatus by which foreign matter in mercury can be automatically removed and clean mercury can be automatically supplied with high efficiency.

The mercury purifying apparatus 1 is an apparatus for removing foreign matter in mercury to purify the mercury. This apparatus comprises at least a mercury-recovery means 3 for recovering mercury 2, a mercury-recovery container 4 for holding the recovered mercury 2 therein and a mercury-supply means 5 for supplying the mercury 2 from the mercury-recovery container and further comprises, between the mercury-recovery means 3 and the mercury-recovery container 4, a foreign-matter-removal means 6 for removing the foreign matter mixed in the mercury.