A media processing device can convey checks at a constant speed passed an information reading position without slipping and without increasing the relay capacity of the transportation roller. The check processing device 1 has two transportation rollers 31 and 32 between the scanning position 52A of the contact image scanner 52 and the separation roller 17 and retard roller 18 that produce a transportation load or transportation load variation. The upstream-side transportation roller 31 turns faster than the downstream transportation roller 32 so that the checks 4 are fed with slack between these transportation rollers 31 and 32. Because of this slack in the part 402 of the check 4 between the transportation rollers 31 and 32, the transportation load from the separation mechanism does not act on the downstream transportation roller 32. The transportation load acting on the transportation roller 32 that feeds the checks 4 to the scanning position 52A can thus be reduced, variation in the transportation load can be suppressed, checks can be conveyed at a constant speed to the scanning position 52A, and a drop in the reading accuracy of the contact image scanner 52 can be prevented.