PURPOSE: To provide the detergent supply device for relaxing restrictions of a use range in the periphery of a faucet, when it is attached to a water tank of a washstand and a sink stand, a bathtub in a bathroom, etc.

CONSTITUTION: A faucet 20 having a drum part 22 for discharging water through water is provided so as to protrude from the surface 11 of a washbowl 11, and in the inside of the washbowl 11, a detergent pump 30 for feeding a detergent by pressure is provided, and a detergent passage 25 having a discharge port 26 for discharging the detergent from the detergent pump 30 is provided in the drum part 22.