The object of the present invention is to provide a method for cutting with gas which uses a cutting tip including a preheating hole for forming a preheating flame with a fuel gas and an oxygen gas for preheating, and an oxygen gas hole for cutting a workpiece by injecting oxygen gas for cutting, and which can decrease an amount of hydrogen gas used by supply a fuel gas to the preheating hole, which is appropriate in both heating and cutting the workpiece, and an apparatus for cutting with gas, and the present invention provides an apparatus for cutting with gas (30) which supplies an oxygen gas, and a fuel gas to a cutting tip (20) including a preheating hole (23) and an oxygen gas hole for cutting (22), wherein the apparatus (30) includes a supply circuit for oxygen gas (50), a supply circuit for hydrogen gas (41), a supply circuit for hydrocarbon-based gas (45), and a gas supply control means (60), and the gas supply control means (60) can alter a ratio of the hydrogen gas and the hydrocarbon-based gas which are supplied to the preheating hole in a case of heating the workpiece and a case of cutting the workpiece.