Wearable device

A wearable device comprising:

• a housing;
• a biometric information obtainer provided on one surface of the housing and configured to obtain biometric information of a user;
• a functional material cartridge accommodated in the housing and configured to store a functional material;
• a mouthpiece connected to the functional material cartridge to discharge the functional material;
• and
• a controller configured to provide a recommendation on inhalation of the functional material based on the biometric information obtained by the biometric information obtainer, wherein
• stress information is derived by comparing first body temperature information, first electrocardiogram (ECG) pattern information, or first heart rate information measured at a first point in time with second body temperature information, second ECG pattern information, or second heart rate information measured at a second point in time, respectively, and
• the controller is configured to determine that there is an increase in a stress index if at least one of an increase in the body temperature of the user, a decrease in an ECG interval, or a decrease in a heart rate cycle does not fall within a set range, and to provide the recommendation on the inhalation of the functional material capable of alleviating stress.