A bank repair method in a manufacturing process of an organic EL display device including first and second banks forming a matrix over a substrate. When a defect portion of a first bank is detected, in each of adjacent concave spaces between which the first bank having the defect portion is located, a candidate forming position is set and a dam portion partitioning the concave space into a first space in a vicinity of the defect portion and a second space outside the vicinity of the defect portion is formed. When denoting sub-pixel region surface area as H and denoting a surface area of a region of a candidate first space overlapping with a sub-pixel region as I, the dam portion is formed at the candidate forming position according to a first forming method when I