A humidity control apparatus comprising: a casing containing first and second adsorption members (14, 15), each of which carrying an adsorbent capable of adsorbing moisture, and a heating medium circuit in which a heating fluid medium for heating or cooling the adsorbents of the first and second adsorption members (14, 15) flows, where the humidity control apparatus brings air into contact with the adsorbents of the first and second adsorption members (14, 15) for humidity control, and supplies the humidity-controlled air to the inside of a room, wherein the humidity control apparatus further includes a holding member which holds the first and second adsorption members (14, 15) and the heating medium circuit together, and is configured to be drawn out of the casing, characterized in that the humidity control apparatus further includes: a first divider plate and a second divider plate which extend from a bottom plate to an upper divider plate, and are perpendicularly supported by the casing to be parallel to right and left plates (25, 26) of the casing, a central divider plate which divides a room between the first and second divider plates (44, 45) into a first humidity control chamber and a second humidity control chamber which are aligned in a vertical direction, and a support plate formed at a lower end of the second humidity control chamber between the first and second divider plates (44, 45), in that the first humidity control chamber contains the first adsorption heat exchanger arranged on the central divider plate, while the second humidity control chamber contains the second adsorption heat exchanger arranged on the support plate, and in that the holding member is comprised of the support plate, the first and second divider plates (44, 45), and the central divider plate being coupled integrally. a casing containing first and second adsorption members (14, 15), each of which carrying an adsorbent capable of adsorbing moisture, and a heating medium circuit in which a heating fluid medium for heating or cooling the adsorbents of the first and second adsorption members (14, 15) flows, where the humidity control apparatus brings air into contact with the adsorbents of the first and second adsorption members (14, 15) for humidity control, and supplies the humidity-controlled air to the inside of a room, wherein the humidity control apparatus further includes a holding member which holds the first and second adsorption members (14, 15) and the heating medium circuit together, and is configured to be drawn out of the casing, characterized in that the humidity control apparatus further includes: a first divider plate and a second divider plate which extend from a bottom plate to an upper divider plate, and are perpendicularly supported by the casing to be parallel to right and left plates (25, 26) of the casing, a central divider plate which divides a room between the first and second divider plates (44, 45) into a first humidity control chamber and a second humidity control chamber which are aligned in a vertical direction, and a support plate formed at a lower end of the second humidity control chamber between the first and second divider plates (44, 45), a first divider plate and a second divider plate which extend from a bottom plate to an upper divider plate, and are perpendicularly supported by the casing to be parallel to right and left plates (25, 26) of the casing, a central divider plate which divides a room between the first and second divider plates (44, 45) into a first humidity control chamber and a second humidity control chamber which are aligned in a vertical direction, and a support plate formed at a lower end of the second humidity control chamber between the first and second divider plates (44, 45), in that the first humidity control chamber contains the first adsorption heat exchanger arranged on the central divider plate, while the second humidity control chamber contains the second adsorption heat exchanger arranged on the support plate, and in that the holding member is comprised of the support plate, the first and second divider plates (44, 45), and the central divider plate being coupled integrally.