To provide a device for turning over pages of a booklet which enables automatic regulation of the contact pressure of turning-over rollers on pages of various booklets.

The device is equipped with a booklet setting stage 34 whereon a booklet 4 is set in a state of being opened to the opposite sides of the seam 4c thereof; a turning-over mechanism 5 which brings the turning-over rollers 13 and 14 into contact with a page 4a on one side of the booklet 4 set on the stage 3, rotates the roller 13 to turn up the page 4a, and then moves the rollers 13 and 14 from the side of the page on one side to the side of the page on the other beyond the seam 4c so as to turn over the page; tactile roller sensors 52 and 54 which detect a slippage occurring between the turning-over rollers 13 and 14 and the page when the rollers 13 and 14 rotate; and a control part 7 which controls the contact pressure of the rollers 13 and 14 on the page on the basis of detected information of the sensors 52 and 54 when they detect the slippage.