Provided is a backup line allocation apparatus that determines which fail lines, in a memory provided with a plurality of backup lines, to allocate the backup lines to, comprising a bit counting section that, for each fail bit contained in each fail line, counts a number of orthogonal fail bits, which is a number of fail bits in a fail line that includes the each fail bit and has an orientation that differs from the orientation of the each fail line, and stores the number of orthogonal fail bits associated with the each fail bit; a weight calculating section that calculates a weighting coefficient for each fail line based on the number of orthogonal fail bits of the fail bits contained in the each fail line, and stores the weighting of the each fail line; and an allocating section that determines which of the fail lines to allocate the backup lines to, based on the relative sizes of the weighting coefficients calculated by the weight calculating section.