Abstract: Process for producing a transistor, particularly a heterojunction bipolar transistor, of the type comprising the known stages consisting in producing layers forming the collector, base and emitter, as well as collector, base and emitter ohmic contacts. The emitter producing stage consists in depositing, on the base layer, two superposed layers making up the emitter, the first of which is a thin layer made up of a first material having a large energy gap, and the second made up of a second material also having a high energy gap. The base ohmic contact is deposited on the first layer of the emitter. The invention also relates to the transistors obtained.