To provide a drainage device for a sanitary fixture, which enables disinfection against bacteria etc. to be performed with low power consumption over a long period of time.

This drainage device 10 for the sanitary fixture includes: a drainage portion 1, which is equipped with a drain outlet 2 allowing the inflow of wastewater, and which is connected to a drain pipe 3 for discharging the wastewater; and an ultraviolet irradiation portion 5, which is equipped with an ultraviolet LED 4 for applying ultraviolet rays for disinfecting the inside of the drainage portion 1. The ultraviolet irradiation portion 5 includes a lighting circuit portion which brings about the pulse lighting of the ultraviolet LED 4, and a control circuit portion 6 which controls the lighting circuit portion so as to decrease the amount of ultraviolet irradiation applied from the ultraviolet LED 4 within a predetermined time along with an increase in the number of times of the lighting of the ultraviolet LED 4.