An ice-maker comprising: an upper tray made of an elastic material, and having a plurality of upper chambers defined therein; a lower tray made of an elastic material, and having a plurality of lower chambers defined therein, wherein in a closed state of the ice-maker, the lower chambers are in contact with the plurality of upper chambers to define a plurality of spherical ice chambers , respectively; a plurality of ejector-receiving openings provided in the upper tray , wherein each the plurality of upper chambers comprises one ejector-receiving opening of the plurality of the ejector-receiving openings ; an upper ejector disposed above the upper tray , wherein the upper ejector is configured to pass through the ejector-receiving openings and to remove each ice from each ice chamber ; a water supply for supplying water for ice-making through the plurality of ejector-receiving openings ; a driver configured to pivot the lower tray , a side wall of the lower tray extending upward along a perimeter of the plurality of lower chambers ; a chamber wall of the upper tray extending downward along a perimeter of the plurality of upper chambers , wherein the chamber wall is at least partly inserted into an internal space of the side wall when the lower tray is pivoted against the upper tray to close the ice chamber ; characterized in that the side wall and the chamber wall are spaced apart from each other by a set spacing (G1, G2); and wherein a groove is defined in an outer surface of the chamber wall to maintain pieces of ice frozen along a perimeter of the chamber wall in an attached state. an upper tray made of an elastic material, and having a plurality of upper chambers defined therein; a lower tray made of an elastic material, and having a plurality of lower chambers defined therein, wherein in a closed state of the ice-maker, the lower chambers are in contact with the plurality of upper chambers to define a plurality of spherical ice chambers , respectively; a plurality of ejector-receiving openings provided in the upper tray , wherein each the plurality of upper chambers comprises one ejector-receiving opening of the plurality of the ejector-receiving openings ; an upper ejector disposed above the upper tray , wherein the upper ejector is configured to pass through the ejector-receiving openings and to remove each ice from each ice chamber ; a water supply for supplying water for ice-making through the plurality of ejector-receiving openings ; a driver configured to pivot the lower tray , a side wall of the lower tray extending upward along a perimeter of the plurality of lower chambers ; a chamber wall of the upper tray extending downward along a perimeter of the plurality of upper chambers , wherein the chamber wall is at least partly inserted into an internal space of the side wall when the lower tray is pivoted against the upper tray to close the ice chamber ; characterized in that the side wall and the chamber wall are spaced apart from each other by a set spacing (G1, G2); and wherein a groove is defined in an outer surface of the chamber wall to maintain pieces of ice frozen along a perimeter of the chamber wall in an attached state. <EOS>