To enable simple confirmation of the presence or absence of a falsification at a falsification preventing pressure-sensitive copy sheet using a back carbon.

The falsification preventing pressure-sensitive copy sheet comprises a back carbon ink layer 5 provided at an opposed surface side of a transfer sheet 2, a developer layer 6 made of a transfer type developer ink provided at a prescribed place between the layer 5 and the sheet 2, and a color developing agent microcapsule layer 7 containing a color developing agent for color developing in a different color from that of the back carbon ink of the layer 5 in a microcapsule provided on a region opposed to the layer 6 of the sheet 2 at least at an opposed surface of an acceptive sheet 3.