To provide an ice making machine with improved ice making efficiency solving the problem of inefficiency in cooling of water due to flowing of water because ice was made by squirting water onto an ice making board.

This ice making machine comprising a cooling means on the outer peripheral surface of an ice making cylinder extended in one direction and generating ice by cooling water supplied into the ice making cylinder by the cooling means is provided with a gas containing means for containing predetermined quantity of gas in the water to be supplied into the ice making cylinder. The cooling means heats the ice making cylinder when deicing the ice generated in the ice making cylinder. The ice making cylinder is provided so as to be extended in the vertical direction, and water is supplied into the ice making cylinder from the lower part. The ice making cylinder deices the ice made therein by pushing out the ice upwardly with the water to be supplied into the ice making cylinder. The ice making cylinder is provided so as to be extended in the vertical direction, a gas pressurizing chamber is provided to the upper end of the ice making cylinder with communicating to the ice making cylinder, and the solubility of gas in the water inside the ice making cylinder is improved by increasing the pressure inside the gas pressurizing chamber while feeding water into the ice making cylinder.