To provide a method and apparatus for detoxicating halogen compound-containing oil capable of quenching unreacted metal sodium and efficiently purifying dehalogenated oil with a little energy.

The treating apparatus 1 for detoxicating halogen compound-containing oil has: a reaction tank 15 dehalogenating halogen compound in oil to be treated with metal sodium and obtaining dehalogenated oil; an impurity extracting tank 19 mixing the dehalogenated oil and a little amount of water, quenching unreacted metal sodium contained in the dehalogenated oil, dissolving the solid impurity contained in the dehalogenated oil into water and/or taking the same into water; and a coalescer type oil water separator 21 separating oil in the dehalogenated oil discharged from the impurity extracting tank 19.