Resumen
PROBLEM TO BE SOLVED: To provide an ink feed circuit apparatus which never malfunctions to lack ink drops because of a sudden change in velocity of a printing head, or the like. SOLUTION: The ink feed circuit apparatus comprises a printing head 1, an ink storage part 2, a conduit 31 and a gas damper 9 between the printing head 1 and ink storage part 2. The gas damper 9 is constituted of a pipe filled with a gas and formed higher than a height 30 of the conduit 31 in a direction agreeing with a vertical direction 25. The gas always stays in a tube 21 because of its low density and a resistance of a surface tension of a meniscus (convex or concave) 19, so that a pressure change due to a sudden change in velocity of the printing head is damped.