Provided is an engine output control device. The gross output power of an engine (12) distributed to at least one main machine (14) and one or more auxiliary machines (15) elicits satisfactory performance from the main machine (14), and controls the engine (12) so as to prevent the gas mileage thereof from decreasing. A total load value calculating portion (222) calculates the value of power consumed by the auxiliary machines (15), and calculates the value of a total load power which is the total of the powers to be supplied to the main machine (14) and the auxiliary machines (15), by adding a target value for the main output power of the engine (12) to be distributed to the main machine (14) to the consumed power value. A gross output value control portion (223) controls the value of gross output power so as to be the value of total load power when the value of total load power is less than a predetermined threshold value, and controls the value of gross output power so as to be the threshold value when the value of total load power is greater than the threshold value.