An electric heater comprising: a substrate; a first plane heating element formed on one surface of the substrate; and a second plane heating element formed on one surface of the substrate so as to be located outside the first plane heating element, wherein the first plane heating element includes: a first pattern portion connecting a start point and an end point thereof, and a pair of first electrode portions connected to the first pattern portion, and wherein the second plane heating element includes: a second pattern portion surrounding a portion of the outer circumference of the first pattern portion, connecting a start point and an end point thereof, and having an opening portion at one side thereof; and a pair of second electrode portions connected to the second pattern portion, wherein the pair of second electrode portions are located in the same direction as the pair of first electrode portions, and wherein the first pattern portion is formed on a first zone, the second pattern portion is formed on a second zone outside the first zone, the start point and the end point of the first pattern portion are located at the outermost side of the first zone, characterized in that the start point and the end point of the second pattern portion are located at the innermost side of the second zone. a substrate; a first plane heating element formed on one surface of the substrate; and a second plane heating element formed on one surface of the substrate so as to be located outside the first plane heating element, wherein the first plane heating element includes: a first pattern portion connecting a start point and an end point thereof, and a pair of first electrode portions connected to the first pattern portion, and a first pattern portion connecting a start point and an end point thereof, and a pair of first electrode portions connected to the first pattern portion, and wherein the second plane heating element includes: a second pattern portion surrounding a portion of the outer circumference of the first pattern portion, connecting a start point and an end point thereof, and having an opening portion at one side thereof; and a pair of second electrode portions connected to the second pattern portion, wherein the pair of second electrode portions are located in the same direction as the pair of first electrode portions, and wherein the first pattern portion is formed on a first zone, the second pattern portion is formed on a second zone outside the first zone, the start point and the end point of the first pattern portion are located at the outermost side of the first zone, characterized in that the start point and the end point of the second pattern portion are located at the innermost side of the second zone. a second pattern portion surrounding a portion of the outer circumference of the first pattern portion, connecting a start point and an end point thereof, and having an opening portion at one side thereof; and a pair of second electrode portions connected to the second pattern portion, wherein the pair of second electrode portions are located in the same direction as the pair of first electrode portions, and wherein the first pattern portion is formed on a first zone, the second pattern portion is formed on a second zone outside the first zone, the start point and the end point of the first pattern portion are located at the outermost side of the first zone, characterized in that the start point and the end point of the second pattern portion are located at the innermost side of the second zone.