An ice maker comprising: a water tray member receiving raw water for ice-making from a water tank; an ice making unit cooling the raw water received in the water tray member and forming ice; a heating unit heating the raw water received in the water tray member; a control unit controlling an operation of the heating unit such that the raw water received in the water tray member is heated before the ice making unit cools the raw water in the water tray member; and a movement generation unit generating a movement of the raw water received in the water tray member, wherein the ice making unit includes an evaporator having an immersion pipe immersed in the raw water received in the water tray member, the ice making unit supplying a low-temperature or high-temperature refrigerant to the evaporator so as to form ice around the immersion pipe or separate ice from the immersion pipe,the heating unit is provided integrally in the ice making unit, and includes a solenoid valve supplying the high-temperature refrigerant generated by a compressor to the evaporator 120 and the immersion pipe, characterized in that after removing air bubbles from the raw water in the water tray member by heating the raw water in the water tray member, the control unit controls the heating unit and the ice making unit to terminate heating the raw water in the water tray member and to start cooling the raw water in the water tray member, the control unit controls an operation of the ice making unit such that a temperature of the raw water received in the water tray member is raised by supplying the high-temperature refrigerant to the evaporator before ice is formed around the immersion pipe for a predetermined duration, the temperature of the raw water received in the water tray member and heated by the heating unit is raised to a set temperature, the set temperature ranging from 10°C to 15°C. a water tray member receiving raw water for ice-making from a water tank; an ice making unit cooling the raw water received in the water tray member and forming ice; a heating unit heating the raw water received in the water tray member; a control unit controlling an operation of the heating unit such that the raw water received in the water tray member is heated before the ice making unit cools the raw water in the water tray member; and a movement generation unit generating a movement of the raw water received in the water tray member, wherein the ice making unit includes an evaporator having an immersion pipe immersed in the raw water received in the water tray member, the ice making unit supplying a low-temperature or high-temperature refrigerant to the evaporator so as to form ice around the immersion pipe or separate ice from the immersion pipe,the heating unit is provided integrally in the ice making unit, and includes a solenoid valve supplying the high-temperature refrigerant generated by a compressor to the evaporator 120 and the immersion pipe, characterized in that after removing air bubbles from the raw water in the water tray member by heating the raw water in the water tray member, the control unit controls the heating unit and the ice making unit to terminate heating the raw water in the water tray member and to start cooling the raw water in the water tray member, the control unit controls an operation of the ice making unit such that a temperature of the raw water received in the water tray member is raised by supplying the high-temperature refrigerant to the evaporator before ice is formed around the immersion pipe for a predetermined duration, the temperature of the raw water received in the water tray member and heated by the heating unit is raised to a set temperature, the set temperature ranging from 10°C to 15°C.