A steam-generating warming device includes a holder including a first surface adapted to face the skin of a wearer and an opposite second surface adapted to face outward and a moist heat generating member held in the holder. The moist heat generating member is configured to generate heat as a result of oxidation of an oxidizable metal, generate steam by making use of the heat, and release the steam through the first surface. The steam-generating warming device further includes a water-impregnated, water-retaining sheet adjoining the moist heating member. The water-retaining sheet is preferably disposed between the moist heat generating member and the second surface.