The disclosure includes 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, and 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. According to the ice maker, the temperature of the raw water received in an ice-making water tray is raised to a preset temperature at the initial stage of an ice making process, thereby preventing the formation of an opaque layer in the central portion of ice.