A liquid discharge apparatus includes a discharge head which discharges a liquid from a discharge port onto a recording medium to form an image, a sub tank which is movable together with the discharge head and which stores the liquid to be supplied to the discharge head, a liquid supplement section which supplements the sub tank with the liquid, a purge section which performs a purge operation in which the liquid in the sub tank is pressurized to be fed to the discharge head, and the liquid in the discharge head is forcibly discharged from the discharge ports, a judging mechanism which judges whether or not an amount of the liquid in the sub tank is not more than a predetermined amount V1, and a controller which controls the liquid supplement section and the purge section.