A balloon infuser comprising: an upper cover on which a scale mark including linear scales is printed; a lower cover fixed to a lower side of the upper cover; a flexible expandable member located inside the upper cover and in which contents are accommodated; an elevation part elevated according to an expansion degree of the expandable member and having a scale indication line on one surface thereof, the scale indication line indicating the scale mark; characterised in that it contains an upper connector holder coupled to an upper elevation part opening located on an upper side of the elevation part; an upper connector coupled to the upper connector holder; an inner shaft coupled to the upper connector, said inner shaft being responsible for elevating the elevation part whilst itself elevating according to the amount of contents; a lower connector holder coupled to a lower opening of the lower cover, through which lower opening the user can approach an infusion opening and through which lower opening may infuse contents; a lower connector coupled to the lower connector holder; an outer shaft coupled to the lower connector; wherein the expandable member covers the inner shaft and the outer shaft, and is firmly fixed and sealed to the inner shaft on an upper side and to the outer shaft on a lower side, and wherein a hollow part is located in the outer shaft, and the inner shaft is inserted into the hollow part to be elevated through a slide movement, wherein the infusion opening communicating with the lower opening is located at a central portion of the outer shaft, wherein the infusion opening communicates with the hollow part through an infusion hole,, wherein a plurality of infusion holes (83, 84) are located in the hollow part wherein the plurality of infusion holes (83, 83) are sealed from the outside by the expandable member, and wherein if contents are infused through the infusion opening, the infused contents are introduced into the hollow part through the infusion hole and are discharged into the expandable member through the plurality of infusion holes (83, 84) to expand the expandable member and lifting the inner shaft, wherein the plurality of infusion holes (83, 84) include: a pair of upper infusion holes located at a central portion of the hollow part; and a pair of lower infusion holes located below the hollow part. an upper cover on which a scale mark including linear scales is printed; a lower cover fixed to a lower side of the upper cover; a flexible expandable member located inside the upper cover and in which contents are accommodated; an elevation part elevated according to an expansion degree of the expandable member and having a scale indication line on one surface thereof, the scale indication line indicating the scale mark; characterised in that it contains an upper connector holder coupled to an upper elevation part opening located on an upper side of the elevation part; an upper connector coupled to the upper connector holder; an inner shaft coupled to the upper connector, said inner shaft being responsible for elevating the elevation part whilst itself elevating according to the amount of contents; a lower connector holder coupled to a lower opening of the lower cover, through which lower opening the user can approach an infusion opening and through which lower opening may infuse contents; a lower connector coupled to the lower connector holder; an outer shaft coupled to the lower connector; wherein the expandable member covers the inner shaft and the outer shaft, and is firmly fixed and sealed to the inner shaft on an upper side and to the outer shaft on a lower side, and wherein a hollow part is located in the outer shaft, and the inner shaft is inserted into the hollow part to be elevated through a slide movement, wherein the infusion opening communicating with the lower opening is located at a central portion of the outer shaft, wherein the infusion opening communicates with the hollow part through an infusion hole,, wherein a plurality of infusion holes (83, 84) are located in the hollow part wherein the plurality of infusion holes (83, 83) are sealed from the outside by the expandable member, and wherein if contents are infused through the infusion opening, the infused contents are introduced into the hollow part through the infusion hole and are discharged into the expandable member through the plurality of infusion holes (83, 84) to expand the expandable member and lifting the inner shaft, wherein the plurality of infusion holes (83, 84) include: a pair of upper infusion holes located at a central portion of the hollow part; and a pair of lower infusion holes located below the hollow part. a pair of upper infusion holes located at a central portion of the hollow part; and a pair of lower infusion holes located below the hollow part.