A laundry washing machine includes a wash tub that allows laundry and water to be loaded therein, a holding unit that separates some of the water in the wash tub and holds the some of the water, where the water contains a substance that was attached to the laundry and that is dissolved therein, a detection unit that detects a predetermined substance contained in the some of the water held by the holding unit and outputs information indicating a result of detection, and a laundry detergent dispenser that dispenses a laundry detergent into the wash tub or instructs a user to add the laundry detergent to the wash tub after the some of the water is separated.