The cutting method of steel for machine structural use includes: forming a mist by mixing a cutting fluid supplied at a supply rate of 0.01 ml/hour to 200 ml/hour and an oxidizing gas containing, by volume %, 21% to 50% of oxygen; and cutting the steel for machine structural use while the mist is blown on the cutting edge surface of a tool and the surface of the steel for machine structural use, wherein the steel for machine structural use includes, by mass %: C: 0.01% to 1.2%, Si: 0.005% to 3.0%, Mn: 0.05% to 3.0%, P: 0.001% to 0.2%, S: 0.001% to 0.35%, N: 0.002% to 0.035%, Al: 0.05% to 1.0%, and the balance consisting of Fe and inevitable impurities in which O is limited to 0.003% or less, and the amount of Al [Al %] and the amount of N [N %] satisfy [Al %]−(27/14)×[N %]≧0.05.