In a known method for producing a dimensionally stable semi-finished product for use in producing fibers from synthetic quartz glass, an SiO2 soot layer is applied to the outer wall of a quartz glass inner cylinder and is subjected to a sintering treatment, wherein a sintering zone moves through the SiO2 soot layer from the outside to the inside. In order to achieve dimensionally accurate and low-deformation production as well as high cost efficiency based on said known method, it is proposed that the sintering treatment be interrupted before the sintering zone reaches the outer wall of the inner cylinder so that an intermediate layer made of synthetic quartz glass containing pores remains at the inner cylinder outer wall. The semi-finished product obtained in such a way is elongated into the optical component, wherein the intermediate layer sinters completely into transparent quartz glass.