Abstract: The invention relates to a method of manufacturing implanted-base, double polysilicon bipolar transistors whose emitter, base and collector are all situated in a single active area. In accordance with the method, first the island isolation (3) defining the active area (4) in the silicon body (1) is provided, which active area forms the collector (5). A first polysilicon layer (6) is deposited on the surface. A first part (6a) of poly I is p-type doped, a second part is n-type doped. By etching, two separate parts are formed from the first poly layer, one part being p-type doped and forming a base terminal (8), the other part being n-type doped and forming a collector terminal (9), said two parts being separated by an intermediate region (16) where the surface of the active area is exposed. The edges of these poly terminals and the exposed parts of the active area are provided with spacers (13, 15) and spacers (14, 16), respectively.