An aerosol generating device includes: a main body including a semi-exterior portion on a surface of which a 1-1st contact electrode and a 1-2nd contact electrode are formed to be apart from each other; a cover detachably coupled to the main body and including a 2-1st contact electrode corresponding to the 1-1st contact electrode and a 2-2nd contact electrode corresponding to the 1-2nd contact electrode; and a controller configured to determine that the cover is mounted on the main body when the 1-1st contact electrode and the 1-2nd contact electrode are electrically connected to each other.