A sterilization apparatus comprising: a flow channel body comprising an inflow unit configured to provide an inflow channel through which water flows in one direction, a discharge unit configured to provide a discharge channel through which water is discharged, and bypass channel units (1415, 1417) through which water bypasses in a different direction from the direction of the water flowing in the inflow unit, wherein the bypass channel units (1415, 1417) include a first bypass channel unit and a second bypass channel unit which are connected to each other and are formed between the inflow unit and the discharge unit, wherein the first bypass channel unit is connected to the inflow unit and the second bypass channel unit is connected to the discharge unit and the bypass channel units (1415, 1417) have bypass channels (c2, d2, e2) through which water is bypassed in a different direction from the inflow unit and the discharge unit; a mounting unit disposed at a joint between the first bypass channel unit and the second bypass channel unit and configured to provide an installation space connected to the bypass channels (c2, d2, e2); a UV light emitting unit disposed in the installation space and configured to emit UV light towards the bypass channels (c2, d2, e2); and a holder coupled to the mounting unit and securing the UV light emitting unit inside the mounting unit, wherein among the bypass channels (c2, d2, e2) formed in the first bypass channel unit and the second bypass channel unit connected to each other, a bypass channel formed in the first bypass channel unit is connected to the inflow channel in a "┘ " shape, a bypass channel formed in the second bypass channel unit is connected to the discharge channel in a "L" shape, and a bypass channel connected the first bypass channel unit to the second bypass channel unit in a " " shape. a flow channel body comprising an inflow unit configured to provide an inflow channel through which water flows in one direction, a discharge unit configured to provide a discharge channel through which water is discharged, and bypass channel units (1415, 1417) through which water bypasses in a different direction from the direction of the water flowing in the inflow unit, wherein the bypass channel units (1415, 1417) include a first bypass channel unit and a second bypass channel unit which are connected to each other and are formed between the inflow unit and the discharge unit, wherein the first bypass channel unit is connected to the inflow unit and the second bypass channel unit is connected to the discharge unit and the bypass channel units (1415, 1417) have bypass channels (c2, d2, e2) through which water is bypassed in a different direction from the inflow unit and the discharge unit; a mounting unit disposed at a joint between the first bypass channel unit and the second bypass channel unit and configured to provide an installation space connected to the bypass channels (c2, d2, e2); a UV light emitting unit disposed in the installation space and configured to emit UV light towards the bypass channels (c2, d2, e2); and a holder coupled to the mounting unit and securing the UV light emitting unit inside the mounting unit, wherein among the bypass channels (c2, d2, e2) formed in the first bypass channel unit and the second bypass channel unit connected to each other, a bypass channel formed in the first bypass channel unit is connected to the inflow channel in a "┘ " shape, a bypass channel formed in the second bypass channel unit is connected to the discharge channel in a "L" shape, and a bypass channel connected the first bypass channel unit to the second bypass channel unit in a " " shape.