Armrest device for vehicle

An armrest device for a vehicle includes a tray module configured to provide a cup holder function, an article storage function, and a table function; a frame module configured to enclose a periphery of the tray module and coupled to a rear seat of the vehicle; and a cover module configured to cover the tray module. The armrest device enables implementation of an arm rest function for allowing a passenger to put an arm on an armrest, as well as the cup holder function, the article storage function, and the table function utilizing a first slide cover having no vertically-extending hole, and a second slide cover formed with a cup holder hole.