A laser machining apparatus includes: a laser oscillator; a control device controlling the laser oscillator; a power-down detection unit detecting a decrease in supply power; a time measurement unit measuring power-down time until the supply power is returned to a predetermined value from when the supply power is decreased under the predetermined value; an electricity storage unit supplying electric power to the control device upon a power outage; and equipment operating abnormally when the supply power is decreased under the predetermined value, and recovering from an abnormal operation when a state of the supply power being smaller than the predetermined value continues for a first predetermined period or longer, the control device stopping the laser machining apparatus when the power-down time is smaller than the first predetermined period and not stopping the laser machining apparatus when the power-down time is equal to or larger than the first predetermined period.