A pneumatic radiation unit according to the present invention includes: a first chamber including a first air discharger configured to discharge air-conditioning air to a second chamber; and the second chamber including a second air discharger configured to discharge the air-conditioning air to a space to be air conditioned, the second chamber being configured to take in the air-conditioning air from the first chamber and discharge the air-conditioning air and radiate heat to the space to be air conditioned. A second aperture ratio of the second air discharger is set to be greater than a first aperture ratio of the first air discharger, or a cross-sectional area of a flow passage of the air-conditioning air in the first chamber is gradually reduced from an upwind side to a downwind side of the flow passage of the air-conditioning air.