Abstract: Provided is a cutting fluid tank for a machine tool, which is capable of sufficiently collecting and removing sludge mixed in a cutting fluid even when a chip conveyor or the like is disposed in a tank main body, and with which a location where sludge remains accumulating on a bottom of the tank main body is less likely to occur even when an operation is restarted after being suspended. A cutting fluid tank includes: a tank main body; a first circulation pump; a sludge transfer nozzle configured to eject the sludge-containing cutting fluid pumped out by the first circulation pump, toward a sludge collection pump; a second circulation; and first agitation nozzles configured to eject the sludge-containing cutting fluid that is pumped out by the second circulation pump, toward predetermined points in the tank main body.