A liquid additive supplying device in a washing machine. The liquid additive supplying device is removably accommodated in an accommodation part of the detergent dispenser system of the washing machine. A magnetic body and a magnetic sensor in the liquid additive supplying device interplay to detect the presence of the liquid additive supplying device within the accommodation part. The liquid additive supplying device includes another pair of magnetic body and magnetic sensor for detecting the amount of liquid additive contained therein.