A laser control device includes: an averaging circuit that applies a primary delay filter to an actual instantaneous value; a data processing unit that applies a primary delay filter to an actual average value H, thereby calculating an actual average value S; a reference value generation unit that generates an reference value; and an output reduction determination unit that determines output reduction. In a case in which pulse on time in the output command value exceeds a sum of the processing period and start-up time of a power supply, if the actual instantaneous value falls below the reference value, it is determined that an output is reduced; and in a case in which the pulse on time is equal to or less than the sum, if the actual average value S falls below the reference value, it is determined that an output is reduced.