A dust cover for a car lamp having excellent moisture control performance, the dust cover comprising: a housing having a housing space formed inside and one open end; and a moisture absorption unit including an air-permeable film and a moisture absorbent which is sealed with the air-permeable film and provided in the housing space, wherein the moisture absorption unit has a moisture absorption rate of 130% or more and a release rate of 4% or less, wherein the moisture absorption rate is measured after exposing a specimen to a temperature of 50∓2°C and a relative humidity of 95∓5% for seven days using a thermohygrostat, and calculated by the following equation: Moisture absorption rate = (Final weight after a certain period of exposure - Initial weight) / Initial weight x 100, and the release rate is measured as a release rate when a specimen is exposed to a constant temperature and humidity condition of 23°C and a relative humidity of 50% for 48 hours and then allowing the specimen to stand in an oven at 70°C for 2 hours and calculated by the following equation: Release rate = (Initial weight - Weight after drying) / Initial weight x 100; and wherein the moisture absorbent includes: at least one or two or more hygroscopic materials selected from the group consisting of magnesium chloride, calcium chloride, and sodium carbonate; a curable inorganic substance including at least one or more selected from the group consisting of magnesium oxide and calcium oxide; a polymer wax; characterized in that the moisture absorbent includes an alkali metal phosphate salt. a housing having a housing space formed inside and one open end; and a moisture absorption unit including an air-permeable film and a moisture absorbent which is sealed with the air-permeable film and provided in the housing space, wherein the moisture absorption unit has a moisture absorption rate of 130% or more and a release rate of 4% or less, wherein the moisture absorption rate is measured after exposing a specimen to a temperature of 50∓2°C and a relative humidity of 95∓5% for seven days using a thermohygrostat, and calculated by the following equation: Moisture absorption rate = (Final weight after a certain period of exposure - Initial weight) / Initial weight x 100, and the release rate is measured as a release rate when a specimen is exposed to a constant temperature and humidity condition of 23°C and a relative humidity of 50% for 48 hours and then allowing the specimen to stand in an oven at 70°C for 2 hours and calculated by the following equation: Release rate = (Initial weight - Weight after drying) / Initial weight x 100; and wherein the moisture absorbent includes: at least one or two or more hygroscopic materials selected from the group consisting of magnesium chloride, calcium chloride, and sodium carbonate; a curable inorganic substance including at least one or more selected from the group consisting of magnesium oxide and calcium oxide; at least one or two or more hygroscopic materials selected from the group consisting of magnesium chloride, calcium chloride, and sodium carbonate; a curable inorganic substance including at least one or more selected from the group consisting of magnesium oxide and calcium oxide; a polymer wax; characterized in that the moisture absorbent includes an alkali metal phosphate salt.