This research was conducted to make the reactor degrade a solution of humic acid using a copper oxide (CuO) catalyst. The designed reactor consists of 2 types of design, the first reactor consists of 8 copper oxide semiconductors (CuO) as catalyst with a sample volume of 1600 ml and a second reactor consisting of 1 copper oxide (CuO) with a sample volume of 25 ml. The light source used is direct sunlight and light in the room. The catalytic process is carried out through photodegradation of a solution of humic acid using the reactor. Variations in irradiation time are carried out for 2, 4, 6 and 8 hours. Absorbance of humic acid before and after irradiation was measured using spronics at 325 nm. The results showed that direct sunlight irradiation gave better results than light rays in the room. The optimum exposure to sunlight is 4 hours with degradation of 32.80% using a second type of reactor.