An impression tray set for edentulous jaw is formed by a maxillary impression tray and a mandibular impression tray respectively including a tray main body having a U-shaped groove on which an impression material is to be applied on a front surface thereof, an engaging part formed on a back surface of the U-shaped groove in a position corresponding to an alveolar ridge of front teeth, and a handle part detachably connected to the engaging part. Each of the maxillary and mandibular impression trays includes projecting parts provided on the back surface at portions corresponding to an alveolar ridge from a first molar part to a premolar part. The projecting parts determine bite position and height in a state in which at least a part of flat top surfaces of the projecting parts contact each other when taking an impression.