A heat exchange and ventilation device of a floor-type comprising: a body casing that constitutes a body shell; an air-supply passage that extends from an outside-air inlet port provided on the body casing and serving as an entrance end to an air-supply outlet port provided on the body casing and serving as an exit end, and supplies exterior air to an interior via inside of the body casing; an air-discharge passage that extends from a circulated-air inlet port provided on the body casing and serving as an entrance end to an air-discharge outlet port provided on the body casing and serving as an exit end, and discharges interior air to an exterior via inside of the body casing; an air-supply blower that forms an air-supply flow in the air-supply passage, which is directed from the entrance end to the exit end thereof; an air-discharge blower that forms an air-discharge flow in the air-discharge passage, which is directed from the entrance end to the exit end thereof; heat exchangers that are provided within the body casing and perform heat exchange between exterior air passing through the air-supply passage and interior air passing through the air-discharge passage and a passage partition member (13a, 13b, 13c) that partitions the air-supply passage and the air-discharge passage, wherein one surface side of the body casing is made to be an opening in its substantial entirety, wherein the heat exchange and ventilation device further comprises a maintenance panel (15, 16, 17) that covers the opening from a front surface of the body casing in an attachable/detachable manner, and at least a part of one of the air-supply passage and the air-discharge passage is formed on a rear side of the other air passage with respect to the passage partition member (13a, 13b, 13c), the rear side being opposite to the one surface side, characterized in that substantially entire area of at least one of the air-supply passage and the air-discharge passage is exposed to the opening, and the passage partition member (13a, 13b, 13c) is attachable and detachable through the opening (la), and when the partition member (13a, 13b, 13c) is removed, a substantially entire area of the air-supply passage and the air-discharge passage is exposed from the opening, wherein the outside-air inlet port, the air-supply outlet port, the circulated-air inlet port, and the air-discharge outlet port are formed on another surface side different from the one surface side. a body casing that constitutes a body shell; an air-supply passage that extends from an outside-air inlet port provided on the body casing and serving as an entrance end to an air-supply outlet port provided on the body casing and serving as an exit end, and supplies exterior air to an interior via inside of the body casing; an air-discharge passage that extends from a circulated-air inlet port provided on the body casing and serving as an entrance end to an air-discharge outlet port provided on the body casing and serving as an exit end, and discharges interior air to an exterior via inside of the body casing; an air-supply blower that forms an air-supply flow in the air-supply passage, which is directed from the entrance end to the exit end thereof; an air-discharge blower that forms an air-discharge flow in the air-discharge passage, which is directed from the entrance end to the exit end thereof; heat exchangers that are provided within the body casing and perform heat exchange between exterior air passing through the air-supply passage and interior air passing through the air-discharge passage and a passage partition member (13a, 13b, 13c) that partitions the air-supply passage and the air-discharge passage, wherein one surface side of the body casing is made to be an opening in its substantial entirety, wherein the heat exchange and ventilation device further comprises a maintenance panel (15, 16, 17) that covers the opening from a front surface of the body casing in an attachable/detachable manner, and at least a part of one of the air-supply passage and the air-discharge passage is formed on a rear side of the other air passage with respect to the passage partition member (13a, 13b, 13c), the rear side being opposite to the one surface side, characterized in that substantially entire area of at least one of the air-supply passage and the air-discharge passage is exposed to the opening, and the passage partition member (13a, 13b, 13c) is attachable and detachable through the opening (la), and when the partition member (13a, 13b, 13c) is removed, a substantially entire area of the air-supply passage and the air-discharge passage is exposed from the opening, wherein the outside-air inlet port, the air-supply outlet port, the circulated-air inlet port, and the air-discharge outlet port are formed on another surface side different from the one surface side.