To provide a residual chlorine meter having a cleaning function for generating a water flow in a liquid to be inspected and polishing the electrode surface appropriately by applying beads-like abrasives carried on that water flow sufficiently to the electrode, and a sterilizer employing that residual chlorine meter.

The residual chlorine meter 21 comprises the inlet 22 of a liquid S to be inspected made in the side face of a container 21, the outlet of the liquid S to be inspected made at the bottom part of the container, a passage 23 of the liquid to be inspected coupled with the inlet 22 and extended substantially horizontally, a section 24 for storing/convecting beads-like abrasives coupled with the passage of the liquid to be inspected, a cover 7 provided above the beads storing/convecting section 24, a plurality of drainage grooves 28 made in the cover, a columnar doughnut-like drainage passage 29 for passing the liquid to be inspected made in the beads storing/convecting section, and a detection electrode 25a and a counter electrode 25b disposed at the beads storing/ convecting section.