Liquid supply method in liquid-jet apparatus

A method for supplying a liquid from a liquid tank to a head tank fixed to a liquid-jet head utilizing a liquid supply device in a liquid-jet apparatus is disclosed. The method includes jetting the liquid droplets from the liquid-jet head while maintaining a meniscus pressure of the liquid-jet head within a predetermined range; detecting the meniscus pressure of the liquid-jet head; carrying out, when the detected meniscus pressure is lower than the predetermined range, a first liquid supply operation such that the detected meniscus pressure of the liquid-jet head being lower than the predetermined range is restored to the predetermined range; and carrying out, while the first liquid supply operation is not being carried out, a second liquid supply operation such that the liquid is supplied to the head tank in an amount less than a liquid-jetted amount computed based on a liquid-jet signal.