Proportional detector intended to detect ionizing radiations for 2-dimension localization.This detector consists of a network of conducting wires (2) forming the anodes of an ionization chamber and operating under avalanche conditions and is characterized in that it comprises a continuous resistive collector (12) with two dimensions and located between the anode (2) wires and the cathode (1) on which the localization of an electron avalanche is effected by electrostatic induction, the reading of the data concerning the electric pulse generated by induction on the collector (12) being effected at the periphery of the latter.