A process for producing a porous quartz glass body containing hydrolyzing a metal dopant precursor and an SiO2 precursor in a flame of a burner to form glass fine particles, and depositing and growing the formed glass fine particles on a base material, in which the burner has at least two nozzles, and in which a mixed gas containing (A) a metal dopant precursor gas, (B) an SiO2 precursor gas, (C) one gas of H2 and O2, and (D) one or more gases selected from the group consisting of a rare gas, N2, CO2, a hydrogen halide and H2O, with a proportion of the gas (D) being from 5 to 70 mol %; and (E) the other gas of H2 and O2 of (C), are fed into different nozzles of the burner from each other.