The present invention relates to an ink supply method and a printing apparatus by which, when an ink supply operation is repeated by using a gas-liquid separation member, damage to the gas-liquid separation member can be reduced to improve the reliability. In order to realize this, an ink supply method for aspirating air in a sub tank via the gas-liquid separation member to supply ink from a supply opening into the sub tank sets a plurality of different amounts as an suction amount of air in the sub tank per a unit time.