A power over fiber system includes a power sourcing equipment, a powered device, an optical fiber cable, a measurer and a control device. The power sourcing equipment includes a semiconductor laser that oscillates with electric power, thereby outputting feed light. The powered device includes a photoelectric conversion element that converts the feed light into electric power. The optical fiber cable transmits the feed light from the power sourcing equipment to the powered device. The measurer measures a distance from the power sourcing equipment to the powered device. The control device controls the power sourcing equipment to output the feed light by changing a laser wavelength thereof for the distance from the power sourcing equipment to the powered device measured by the measurer.