A refrigerator comprising: a storage chamber configured to store food; a cooler configured to supply cold air into the storage chamber; a first temperature sensor configured to sense a temperature within the storage chamber; a first tray assembly 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 assembly configured to define another portion of the ice making cell, the second tray assembly being connected to a driver to contact the first tray assembly in an ice making process and to be spaced apart from the first tray assembly in an ice separation process; a water supply part configured to supply the water into the ice making cell; a second temperature sensor configured to sense a temperature of the water or the ice within the ice making cell; a heater disposed adjacent to the second tray assembly; further comprising an additional heater located around the first tray being an ice separation heater, and a controller configured to control the heater, the ice separation heater, the cooler and the driver, wherein the controller controls the cooler so that the cold air is supplied to the ice making cell after the second tray assembly moves to an ice making position when the water is completely supplied to the ice making cell, the controller controls the second tray assembly so that the second tray assembly moves in a reverse direction after moving to an ice separation position in a forward direction so as to take out the ice in the ice making cell when the ice is completely made in the ice making cell, the controller performs control so that the supply of the water starts after the second tray assembly moves to a water supply position in the reverse direction when the ice is completely separated, the controller controls the heater to be turned on in at least partial section while the cooler supplies the cold air so that bubbles dissolved in the water within the ice making cell moves from a portion, at which the ice is made, toward the water that is in a liquid state to make transparent ice, the first tray assembly comprises a first tray and a first tray case (300, 340) supporting the first tray, the second tray assembly comprises a second tray and a second tray case (360, 400) supporting the second tray, and a degree of attachment between the first tray and the ice is less than a degree of attachment between the first tray case (300, 340) and the ice or a degree of attachment between metal and the ice. a storage chamber configured to store food; a cooler configured to supply cold air into the storage chamber; a first temperature sensor configured to sense a temperature within the storage chamber; a first tray assembly 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 assembly configured to define another portion of the ice making cell, the second tray assembly being connected to a driver to contact the first tray assembly in an ice making process and to be spaced apart from the first tray assembly in an ice separation process; a water supply part configured to supply the water into the ice making cell; a second temperature sensor configured to sense a temperature of the water or the ice within the ice making cell; a heater disposed adjacent to the second tray assembly; further comprising an additional heater located around the first tray being an ice separation heater, and a controller configured to control the heater, the ice separation heater, the cooler and the driver, wherein the controller controls the cooler so that the cold air is supplied to the ice making cell after the second tray assembly moves to an ice making position when the water is completely supplied to the ice making cell, the controller controls the second tray assembly so that the second tray assembly moves in a reverse direction after moving to an ice separation position in a forward direction so as to take out the ice in the ice making cell when the ice is completely made in the ice making cell, the controller performs control so that the supply of the water starts after the second tray assembly moves to a water supply position in the reverse direction when the ice is completely separated, the controller controls the heater to be turned on in at least partial section while the cooler supplies the cold air so that bubbles dissolved in the water within the ice making cell moves from a portion, at which the ice is made, toward the water that is in a liquid state to make transparent ice, the first tray assembly comprises a first tray and a first tray case (300, 340) supporting the first tray, the second tray assembly comprises a second tray and a second tray case (360, 400) supporting the second tray, and a degree of attachment between the first tray and the ice is less than a degree of attachment between the first tray case (300, 340) and the ice or a degree of attachment between metal and the ice.