A heating element, comprising: a substrate; a first bus bar provided on the substrate; a second bus bar which is provided on the substrate so as to be opposite to the first bus bar; and a heating pattern which is provided to electrically connect the first bus bar and the second bus bar, wherein the heating pattern includes a first pattern region (B) which is in contact with the first bus bar and a second pattern region (C) which is in contact with the second bus bar and the first pattern region (B) and the first pattern region (B) has an opening region (A) which serves as a communication window and a ratio of a sheet resistance of the second pattern region (C) with respect to a sheet resistance of the first pattern region (B) is 1 or more, wherein the first pattern region (B) includes heating lines which connect the first bus bar and the second pattern region (C), characterised in that a deviation of resistance between both ends of the heating lines on the first pattern region (B) connecting the first bus bar and the second pattern region (C) is 10% or less, meaning a deviation of resistance between all the heating lines on the first pattern region (B) connecting the first bus bar and the second pattern region (C) is 10% or less, a ratio of a sheet resistance of the first bus bar with respect to a sheet resistance of the first pattern region (B) is 0.1 or less, and the line width of the heating line of the heating pattern of the first pattern region (B) is 0.5 to 10 times of a value obtained by multiplying a line width of the second pattern region (C) and an interval between lines of the first pattern region (B) or an interval between lines of the second pattern region (C). a substrate; a first bus bar provided on the substrate; a second bus bar which is provided on the substrate so as to be opposite to the first bus bar; and a heating pattern which is provided to electrically connect the first bus bar and the second bus bar, wherein the heating pattern includes a first pattern region (B) which is in contact with the first bus bar and a second pattern region (C) which is in contact with the second bus bar and the first pattern region (B) and the first pattern region (B) has an opening region (A) which serves as a communication window and a ratio of a sheet resistance of the second pattern region (C) with respect to a sheet resistance of the first pattern region (B) is 1 or more, wherein the first pattern region (B) includes heating lines which connect the first bus bar and the second pattern region (C), characterised in that a deviation of resistance between both ends of the heating lines on the first pattern region (B) connecting the first bus bar and the second pattern region (C) is 10% or less, meaning a deviation of resistance between all the heating lines on the first pattern region (B) connecting the first bus bar and the second pattern region (C) is 10% or less, a ratio of a sheet resistance of the first bus bar with respect to a sheet resistance of the first pattern region (B) is 0.1 or less, and the line width of the heating line of the heating pattern of the first pattern region (B) is 0.5 to 10 times of a value obtained by multiplying a line width of the second pattern region (C) and an interval between lines of the first pattern region (B) or an interval between lines of the second pattern region (C). <EOS>