PURPOSE: To remove foreign matters and bacteria from cutting oil and easily, economically provide recycled cutting oil by roughly filtering cutting oil sucked up from a reservoir of a machine tool, then microfiltering.

CONSTITUTION: Cutting oil is sucked up from a reservoir of a machine tool with a pump, filtered to remove large foreign matters to obtain roughly filtered cutting oil. This cutting oil is sucked up with a pump and passed through a second filter to remove most bacteria to obtain microfiltered cutting oil, which is returned to the reservoir of the machine tool. The recycling equipment is relatively less expensive and portable, and easily combined with a wide range of machine tools for recycling cutting oil.