The present invention relates to a tumbler for enabling an additive stored in a storage space to be added, in a fixed amount, to drinking water by a pumping means such that a user can drink the drinking water, and the present invention comprises: a drinking water tray of which an upper part is opened, and a lower end is shielded so as to form, on the inner side thereof, a storage space for storing drinking water or a beverage; an additive storage tray of which an upper part is opened, and a lower end is shielded so as to form a storage space in which an additive, to be drunk by being added to water, is stored.