A cooker, comprising: a cavity including a cooking chamber the cavity having an opening; a door selectively opening and closing the cooking chamber; at least one heating source (17, 18, 19) providing heat for cooking food inside the cooking chamber; and a cleaning apparatus supplying cleaning water to the inside of the cooking chamber, characterized in that an enamel coating layer including a phosphate-based ingredient is provided on an inner surface of the cooking chamber, and the cleaning apparatus includes: a water tank that stores cleaning water; and a supplying unit supplying the cleaning water stored in the water tank to the inside of the cooking chamber, the supplying unit can move to be exposed to the inside of the cooking chamber or be positioned at an upper position that is outside of the cooking chamber, a first cover is positioned above the supplying unit to cover the opening part when the supplying unit is exposed to the inside of the cooking chamber and a second cover is positioned below the supplying unit to cover the opening part when the supplying unit is positioned outside the cooking chamber, wherein the cleaning water supplied to the inside of the cooking chamber is heated by a heating source (17, 18, 19; 47). a cavity including a cooking chamber the cavity having an opening; a door selectively opening and closing the cooking chamber; at least one heating source (17, 18, 19) providing heat for cooking food inside the cooking chamber; and a cleaning apparatus supplying cleaning water to the inside of the cooking chamber, characterized in that an enamel coating layer including a phosphate-based ingredient is provided on an inner surface of the cooking chamber, and the cleaning apparatus includes: a water tank that stores cleaning water; and a supplying unit supplying the cleaning water stored in the water tank to the inside of the cooking chamber, the supplying unit can move to be exposed to the inside of the cooking chamber or be positioned at an upper position that is outside of the cooking chamber, a first cover is positioned above the supplying unit to cover the opening part when the supplying unit is exposed to the inside of the cooking chamber and a second cover is positioned below the supplying unit to cover the opening part when the supplying unit is positioned outside the cooking chamber, a water tank that stores cleaning water; and a supplying unit supplying the cleaning water stored in the water tank to the inside of the cooking chamber, the supplying unit can move to be exposed to the inside of the cooking chamber or be positioned at an upper position that is outside of the cooking chamber, a first cover is positioned above the supplying unit to cover the opening part when the supplying unit is exposed to the inside of the cooking chamber and a second cover is positioned below the supplying unit to cover the opening part when the supplying unit is positioned outside the cooking chamber, the supplying unit can move to be exposed to the inside of the cooking chamber or be positioned at an upper position that is outside of the cooking chamber, a first cover is positioned above the supplying unit to cover the opening part when the supplying unit is exposed to the inside of the cooking chamber and a second cover is positioned below the supplying unit to cover the opening part when the supplying unit is positioned outside the cooking chamber, wherein the cleaning water supplied to the inside of the cooking chamber is heated by a heating source (17, 18, 19; 47).