The development of new instruments for low-energy atoms is becoming of considerable interest in various research fields, such as the direct detection of dark matter, micro-dosimetry, the study of the atmospheres of the Solar System bodies, as well as in the direct measurement of low-energy cosmic rays. In the last few years, our working group, at INFN Pisa Laboratory, has been involved in the development of a gas detector based on a Micro-Megas (MM) device working in a low-pressure regime. Within the Micro-Pattern Gas Detector family, the intrinsic characteristics of the
MM device represent the most promising features for constructing a new detector to be operated as an imaging device gas chamber. The main goal of the experimental activity was the development of an electrode configuration optimizing the instrument performance for atoms in the energy range of 1-100 keV, with good energy and angular resolution in a single compact instrument. The dependence of the gain, the energy resolution from the amplification field, gas pressure, and drift field have been deeply investigated, both with x-rays sources and ionized helium beams. Here a summary of a measurements campaign devoted to a technical characterization of a MM bulk filled with a gas mixture maintained at low pressure is presented.