We describe in this paper the performance under synchrotron radiation of a sealed gaseous detector, Vantec-1, operating at high pressure and less prone to discharges. It is consequently operating at high gain (> 10(5)) at high local counting rates up to 10(6) cps/mm(2). To achieve these characteristics, a thin resistive layer is used on a glass plate between the mesh and the readout anode. The performance achieved with this detector is suited for applications in X-ray diffraction and synchrotron radiation. This detector has shown high reliability over time under harsh synchrotron radiation environment and robustness in manufacturing environment. (c) 2006 Elsevier B.V. All rights reserved.