A silica glass containing TiO.sub.2, which has a fictive temperature of at most 1,200.degree. C., a F concentration of at least 100 ppm and a coefficient of thermal expansion of 0.+-.200 ppb/.degree. C. from 0 to 100.degree. C.A process for producing a silica glass containing TiO.sub.2, which comprises a step of forming a porous glass body on a target quartz glass particles obtained by flame hydrolysis of glass-forming materials, a step of obtaining a fluorine-containing porous glass body, a step of obtaining a fluorine-containing vitrified glass body, a step of obtaining a fluorine-containing formed glass body and a step of carrying out annealing treatment.