A silicon single crystal growing apparatus based on a Czochralski method arranges a graphite crucible inside a graphite heater for heating and a quartz crucible inside the graphite crucible and grows a crystal from a raw material melt filling the quartz crucible, and includes a heater outer heat-insulating member outside the graphite heater, a crucible lower heat-insulating member below the graphite crucible, a crucible upper heat-insulating member above straight bodies of the graphite and quartz crucibles, a crucible outer heat-insulating member outside the straight body of the graphite crucible, a crucible inner heat-insulating member inside the straight bodies of the graphite crucible and the quartz crucible, and a heat shielding member above a liquid surface of the raw material melt, the graphite crucible and the quartz crucible being movable upward and downward in a space enclosed with the crucible upper heat-insulating, crucible outer heat-insulating, and crucible inner heat-insulating members.