According to one embodiment, a sheet separator has a first driving roller and a pressing body. The first driving roller rotates about a first rotation shaft. The first driving roller conveys a sheet bundle including a plurality of sheets. The pressing body is capable of approaching the first driving roller. The first driving roller is rotatable in a first direction with the sheet bundle sandwiched between the first driving roller and the pressing body. The pressing body pivots in the first direction about the first rotation shaft with the sheet bundle sandwiched between the first driving roller and the pressing body to cause the plurality of sheets to deviate from one another at edges.