A nozzle holding mechanism configured to hold a held surface of a nozzle to a nozzle-holding surface of a head using negative pressure, the nozzle holding mechanism comprising: a recess provided on one of the nozzle-holding surface or the held surface; a pressure adjusting means connected to the recess; characterized by a magnet attached to the head so as to face the recess and to have a changeable positional relationship with the nozzle-holding surface, the magnet being arranged such that at a normal position the magnet is separated from the nozzle-holding surface by an elastic body in a state in which the nozzle is not being held by the nozzle-holding surface, the magnet being configured to provide a magnetic force to hold the nozzle to the head only by means of the magnetic force; and a metal member attached to the held surface of the nozzle at a position opposite the magnet on the held surface of the nozzle and made from a material attracted to the magnet; wherein when negative pressure is supplied via the pressure adjusting means to a pressure adjustment chamber formed from the recess that is connected to the nozzle-holding surface and the held surface, due to the negative pressure the held surface is configured to be sucked to the nozzle-holding surface, and the magnet is configured to be moved against biasing of the elastic body from the normal position to an attract position at which the metal member is configured to be attracted to the magnet by magnetic force, and, when positive pressure is supplied to the pressure adjustment chamber via the pressure adjusting means, due to the biasing by the elastic body and the positive pressure the magnet is configured to be moved to the normal position such that the attraction of the metal member to the held surface is released. a recess provided on one of the nozzle-holding surface or the held surface; a pressure adjusting means connected to the recess; characterized by a magnet attached to the head so as to face the recess and to have a changeable positional relationship with the nozzle-holding surface, the magnet being arranged such that at a normal position the magnet is separated from the nozzle-holding surface by an elastic body in a state in which the nozzle is not being held by the nozzle-holding surface, the magnet being configured to provide a magnetic force to hold the nozzle to the head only by means of the magnetic force; and a metal member attached to the held surface of the nozzle at a position opposite the magnet on the held surface of the nozzle and made from a material attracted to the magnet; wherein when negative pressure is supplied via the pressure adjusting means to a pressure adjustment chamber formed from the recess that is connected to the nozzle-holding surface and the held surface, due to the negative pressure the held surface is configured to be sucked to the nozzle-holding surface, and the magnet is configured to be moved against biasing of the elastic body from the normal position to an attract position at which the metal member is configured to be attracted to the magnet by magnetic force, and, when positive pressure is supplied to the pressure adjustment chamber via the pressure adjusting means, due to the biasing by the elastic body and the positive pressure the magnet is configured to be moved to the normal position such that the attraction of the metal member to the held surface is released.