Roentgen examinations of stomach, as one of the countermeasures against cancer, have been investigated by many researchers. Gastro-phantoms are necessary for the fundamental experiments to increase the discernment of roentgenography of stomach. We introduce our gastro-phantom here in-after in this paper and hope that opinions and criticism will be given. Prior to the trial production of our gastro-phantom, first of all, the following values were reguired. 1) Adult patient's abdominis thickness and width values. 2) Stomach width in adult's plenitude and the position in the abdomen. 3) Roentgenograph of adult's stomach in his plenitude and the surrounding density of the photography. Referring to these values the present gastro-phantom was made out of acrylic plastics, which is easily obtained, to be used in the hydro-phantom equivalent to the thickness of abdominis.
