A lubricating oil composition comprising, based on the total amount of the lubricating oil composition: (i) a lubricant base oil, (ii) 0.12% by mass to 2.5% by mass of a neutral phosphorus-based compound represented by general formula or: wherein in general formulae and, R 3, R 4 and R 5 represent, as a hydrocarbon group, an aryl group having 6 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, wherein R 3, R 4 and R 5 may be the same or different, (iii) 0.1% by mass to 0.8% by mass of an acidic phosphorus-based compound represented by general formula or: wherein in general formula and general formula, R 6 and R 7 represent hydrogen or a hydrocarbon group having 8 to 30 carbon atoms, wherein at least one of R 6 and R 7 is a hydrocarbon group having 8 to 30 carbon atoms, and wherein R 6 and R 7 may be the same or different, (iv) 0.03% by mass to 0.3% by mass of a sulfur-based compound selected from thiadiazole-based compound represented by general formula and a polysulfide-based compound represented by general formula: wherein in general formula, R 9 and R 10 each independently represent an alkyl group having 1 to 30 carbon atoms, which may be the same or different, X1 and X2 each independently represent an integer of 1 to 3, R 11 - Y -R 12 wherein in general formula, R 11 and R 12 each independently represent an alkyl group having 1 to 24 carbon atoms, an aryl group having 3 to 20 carbon atoms or an alkylaryl group having 7 to 20 carbon atoms, wherein R 11 and R 12 may be the same or different, and Y is an integer of 2 to 8, and (v) 0.01% by mass to 0.5% by mass of a secondary amine compound, which is a compound represented by formula: wherein R 1 and R 2 each independently represent a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, wherein the substituent is a hydroxyl group, the lubricating oil composition having a flash point of 172°C or higher, as determined by the C.O.C method in accordance with JIS-K-2265. (i) a lubricant base oil, (ii) 0.12% by mass to 2.5% by mass of a neutral phosphorus-based compound represented by general formula or: wherein in general formulae and, R 3, R 4 and R 5 represent, as a hydrocarbon group, an aryl group having 6 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, wherein R 3, R 4 and R 5 may be the same or different, (iii) 0.1% by mass to 0.8% by mass of an acidic phosphorus-based compound represented by general formula or: wherein in general formula and general formula, R 6 and R 7 represent hydrogen or a hydrocarbon group having 8 to 30 carbon atoms, wherein at least one of R 6 and R 7 is a hydrocarbon group having 8 to 30 carbon atoms, and wherein R 6 and R 7 may be the same or different, (iv) 0.03% by mass to 0.3% by mass of a sulfur-based compound selected from thiadiazole-based compound represented by general formula and a polysulfide-based compound represented by general formula: wherein in general formula, R 9 and R 10 each independently represent an alkyl group having 1 to 30 carbon atoms, which may be the same or different, X1 and X2 each independently represent an integer of 1 to 3, R 11 - Y -R 12 wherein in general formula, R 11 and R 12 each independently represent an alkyl group having 1 to 24 carbon atoms, an aryl group having 3 to 20 carbon atoms or an alkylaryl group having 7 to 20 carbon atoms, wherein R 11 and R 12 may be the same or different, and Y is an integer of 2 to 8, and (v) 0.01% by mass to 0.5% by mass of a secondary amine compound, which is a compound represented by formula: wherein R 1 and R 2 each independently represent a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, wherein the substituent is a hydroxyl group,