A pressurizing/depressurizing method of a liquid ejecting apparatus which includes a print head which ejects liquid, and a supply unit which supplies the liquid to the print head, the method including depressurizing/pressure accumulating in which a depressurization buffer tank is depressurized, and a pressure is accumulated; pressurizing/pressure accumulating in which a pressurization buffer tank is pressurized, and a pressure is accumulated; depressurizing in which the liquid is depressurized so that a pressure is lower than an atmospheric pressure in the supply unit using the depressurization buffer tank; and pressurizing in which the liquid is pressurized so that the pressure is higher than the atmospheric pressure in the supply unit using the pressurization buffer tank.