A refrigerator comprising: a storage chamber configured to store food; a cold air supply part configured to supply cold air to the storage chamber; a first tray configured to define a portion of an ice making cell that is a space in which water is phase-changed into ice by the cold air; a second tray configured to define the other portion of the ice making cell, the second tray being in contact with the first tray in an ice making process and spaced apart from the first tray in an ice separation process; a water supply part configured to supply the water to the ice making cell; a heater (290, 430) disposed adjacent to at least one of the first tray or the second tray; and a controller configured to control the heater (290, 430), wherein the controller is configured to control: the second tray to stand by for a predetermined time after a water supply to the ice making cell is completed at a water supply position; the second tray to move to an ice making position after standing by for the predetermined time so that the cold air supply part supplies the cold air to the ice making cell; the second tray to move to an ice separation position in a forward direction so as to take the ice out of the ice making cell after the ice is completely generated in the ice making cell; and the second tray to move from the ice separation position to the water supply position in a reverse direction after a separation of the ice is completed, wherein the second tray comprises a circumferential wall configured to surround a portion of the first tray at the water supply position, wherein, at the water supply position, an upper end of the circumferential wall is disposed higher than a bottom surface of the first tray, characterized in that at the water supply position, a height from the bottom surface of the first tray to the upper end of the circumferential wall is greater than 1/2 of a height from the bottom surface of the first tray to an upper end of the ice making cell. a storage chamber configured to store food; a cold air supply part configured to supply cold air to the storage chamber; a first tray configured to define a portion of an ice making cell that is a space in which water is phase-changed into ice by the cold air; a second tray configured to define the other portion of the ice making cell, the second tray being in contact with the first tray in an ice making process and spaced apart from the first tray in an ice separation process; a water supply part configured to supply the water to the ice making cell; a heater (290, 430) disposed adjacent to at least one of the first tray or the second tray; and a controller configured to control the heater (290, 430), wherein the controller is configured to control: the second tray to stand by for a predetermined time after a water supply to the ice making cell is completed at a water supply position; the second tray to move to an ice making position after standing by for the predetermined time so that the cold air supply part supplies the cold air to the ice making cell; the second tray to move to an ice separation position in a forward direction so as to take the ice out of the ice making cell after the ice is completely generated in the ice making cell; and the second tray to move from the ice separation position to the water supply position in a reverse direction after a separation of the ice is completed, wherein the second tray comprises a circumferential wall configured to surround a portion of the first tray at the water supply position, wherein, at the water supply position, an upper end of the circumferential wall is disposed higher than a bottom surface of the first tray, characterized in that at the water supply position, a height from the bottom surface of the first tray to the upper end of the circumferential wall is greater than 1/2 of a height from the bottom surface of the first tray to an upper end of the ice making cell. the second tray to stand by for a predetermined time after a water supply to the ice making cell is completed at a water supply position; the second tray to move to an ice making position after standing by for the predetermined time so that the cold air supply part supplies the cold air to the ice making cell; the second tray to move to an ice separation position in a forward direction so as to take the ice out of the ice making cell after the ice is completely generated in the ice making cell; and the second tray to move from the ice separation position to the water supply position in a reverse direction after a separation of the ice is completed, wherein the second tray comprises a circumferential wall configured to surround a portion of the first tray at the water supply position, wherein, at the water supply position, an upper end of the circumferential wall is disposed higher than a bottom surface of the first tray, characterized in that at the water supply position, a height from the bottom surface of the first tray to the upper end of the circumferential wall is greater than 1/2 of a height from the bottom surface of the first tray to an upper end of the ice making cell.