  The aim of the ArDM project is the development and operation of a one ton
double-phase liquid argon detector for direct Dark Matter searches. The
detector measures both the scintillation light and the ionization charge from
ionizing radiation using two independent readout systems. This paper briefly
describes the detector concept and presents preliminary results from the ArDM
R&D program, including a 3 l prototype developed to test the charge readout
system.
