An ice making machine may include an ice tray having a plurality of recessed parts and a cold air duct having a cold air inflow port connected with a cold air supply port and one cold air outlet port facing the ice tray on an upper side. A size of the cold air outlet port is smaller than a size of an ice making face of the ice tray having a contour which includes the plurality of the ice making recessed parts along edges of openings of the plurality of the ice making recessed parts, and the cold air outlet port faces a center portion of the ice making face. It is preferable that an opening area of the cold air outlet port is 50% or less of an area of the ice making face and/or is smaller than an opening area of the cold air inflow port.