To provide filling liquid for a liquid discharge apparatus having improved corrosion durability while maintaining the intrinsic functions of the filling liquid filled into a liquid flow passage, to provide a head device for a liquid discharge apparatus, the liquid discharge apparatus, cleaning liquid for the liquid discharge apparatus and a method for cleaning the liquid discharge apparatus.

For inhibiting the corrosion and elution of metal in a liquid flow passage caused by the filling liquid and the cleaning liquid, a corrosion-elution preventive for inhibiting the corrosion and elution of metal in the liquid flow passage is incorporated into the filling liquid and cleaning liquid.