An object of the present invention is to provide a heat-generating device with which a warm sensation is persistently perceived, and which can effectively exert a heating effect. In a heat-generating device that is used by being attached to skin, (1) a packaging material constituting a skin attachment surface of a housing is formed of a laminated sheet in which at least a moisture absorption layer that absorbs moisture and a moisture barrier layer that blocks penetration of moisture are laminated in this order from the adhesive layer, (2) an adhesive layer is partially provided on a surface of the moisture absorption layer, and (3) a warming agent that allows an enhanced warm sensation to be perceived in the presence of moisture is contained in at least one of the adhesive layer and the moisture absorption layer. This heat-generating device thereby has improved persistence of a perceived warm sensation, and can exert a markedly high heating effect.