Printing machine

A printing machine comprising:

• an inkjet head including a piezoelectric element set configured to vibrate to propel out droplets of ink;
• a degasser configured to degas flux of ink to be supplied to the inkjet head;
• a memory configured to store therein a threshold table having mutually associated a threshold set of a determination parameter preset for a determination on a degassing process and a domain set of a control parameter of a physical amount constituting a cause of bubble formation in ink;
• and
• a controller configured to control driving the degasser, the controller being adapted to calculate a value of the determination parameter from a set of image data of a print job, and operate as the value is equal to or greater than a threshold in the threshold table read out of the memory, to drive the degasser.