Abstract: A hyperbaric gas treatment device applicable to any part of the body for therapeutic topical treating of a skin lesion at the body part. A resilient pad is provided with a central opening therethrough in its thickness direction whose periphery at one major pad surface registers with the periphery of a hole provided through gas-impervious transparent flexible sheet material which encases the pad. The pad casing is hermetically penetrated by a gas inlet fitting arranged to discharge treating gas into the central opening either directly, by extending laterally through the pad to pierce the wall of the opening, or indirectly, by extending between the casing and a peripheral surface portion of the pad so as to communicate with the opening by way of paths between the casing and the pad periphery which link with paths between the casing and at least one of the major pad surfaces.