To provide a cutting blade holder to hold a cutting blade which can easily and quickly cut to open so-called paper packs.

This cutting blade holder holds the cutting blade 32 to cut so-called paper packs. For such a cutting blade holder, the holder body 11 is constituted of first and second guide plates 12 and 13. In this case, the first and the second guide plates 12 and 13 are crossed into an approximately orthogonal state in order to make them internally come into contact with the external surfaces of plate-form walls being under an adjacent state to each other of a paper pack. Then, on the first guide plate 12, a slit 15 is formed at a location being arranged along the crossing line 14. Then, a cutter knife K is fixed in such a manner that the cutting blade 32 may be exposed downward from the slit 15 to a guide plate 17 for cutter.