An ink composition is provided which has excellent initial filling characteristics and continuous printing stability even in the case of an ink composition (for example, dissolved nitrogen is equal to or greater than 5 ppm) which is almost not deaerated or an ink composition (for example, dissolved nitrogen is equal to or greater than 7 ppm) which is not deaerated at all. The ink composition includes an alkylene oxide adduct (A) of acetylenic glycol in which a main chain has 12 or more carbon atoms, acetylenic glycol (B) in which a main chain has 10 or more carbon atoms, and polyoxyalkylene alkyl ether (C).