A method is used for removing a metal contaminant deposited on a quartz member selected from the group consisting of a reaction tube, wafer boat, and heat-insulating cylinder of a vertical heat processing apparatus for a semiconductor process. The method includes obtaining the quartz member unattached to the vertical heat processing apparatus; then, performing diluted hydrofluoric acid cleaning of cleaning the quartz member by use of diluted hydrofluoric acid; then, performing first purified water cleaning of cleaning the quartz member by use of purified water; then, performing hydrochloric acid cleaning of cleaning the quartz member by use of hydrochloric acid; and then, performing second purified water cleaning of cleaning the quartz member by use of purified water.