Abstract: A process for producing silica glass fibers comprising:a step of preparing a silica glass fiber spinning solution by adding a polymerization regulator to a silica sol solution obtained by the hydrolysis and condensation of a silicon alkoxide in the presence of an acid catalyst;a step of spinning the spinning solution into gel fibers by extruding the spinning solution from nozzles;a step of applying an oiling agent containing substantially no water or lower alcohol to the gel fibers;a step of forming a fiber cake by winding the oiled gel fibers on a tube or bobbin;a step of aging the gel fibers constituting the fiber cake;a step of sintering the gel fibers unwound from the fiber cake after the aging step, to form silica glass fibers.