  To solve the discharge of the standard Bulk Micromegas and GEM detector, the
GEM-Micromegas detector was developed in Institute of High Energy Physics.
Taking into account the advantages of the two detectors, one GEM foil was set
as a preamplifier on the mesh of Micromegas in the structure and the GEM
preamplification decreased the working voltage of Micromegas to reduce the
effect of the discharge significantly. In the paper, the performance of
detector in X-ray beam was studied at 1W2B laboratory of Beijing Synchrotron
Radiation Facility. Finally, the result of the energy resolution under various
X-ray energies was given in different working gases. It indicated that the
GEM-Micromegas detector had the energy response capability in all the energy
range and it could work better than the standard Bulk-Micromegas.
