Ice maker

An ice maker comprising:

• an upper tray that includes a plurality of upper cells that each have a hemispherical shape, each of the plurality of upper cells shaped to be upwardly convex;
• an ice making tube disposed at outer circumferential surfaces of the upper cells and configured to cool each of the upper cells;
• a lower tray that is rotatably connected to the upper tray, the lower tray comprising:
• a tray body in which a plurality of lower cells are formed, each of the plurality of lower cells being configured to have a hemispherical shape and being configured to be downwardly convex;
• and an upper frame comprising:
• a plurality of communication holes each with a same diameter as a top surface of each of the lower cells;
• and a hook part that is configured to extend horizontally and vertically from an edge of the communication holes, where an upper end of the hook part is configured to be higher than the top surface of the lower cells;
• a rotation shaft connecting a rear end of the lower tray and a rear end of the upper tray, and configured to rotate the lower tray with respect to the upper tray, wherein the lower tray is configured to be placed at a water supply position by rotating in a first direction, and opened surfaces of the plurality of upper cells and opened surfaces of the plurality of lower cells are configured to be spaced apart from and face each other at the water supply position, wherein the plurality of lower cells of the lower tray receive water for making ice at the water supply position, wherein, when the water level reaches the upper end of the hook part the lower tray is configured to further rotate in the first direction to an ice making position where the opened surfaces of the plurality of lower cells are in closed contact with the opened surfaces of the plurality of upper cells of the upper tray, to define a complete sphere shape, and wherein, when the lower tray rotates, the upper tray is maintained to be stationary.