To provide a folding machine capable of shortening the adjusting time of folding rollers.

The folding machine has a plurality of the folding rollers 1-3, and a slat 4 drawing in a tip end of paper to a position of a stopper 7, and performs folding machining on the paper by the combination of the folding rollers and the slat. The slat 4 is made from two parallel metallic plates 5, 6, and has a shape opening at a front part and a rear part and provided with a slit groove in a paper feeding direction. A stopper 9 is provided so as to come and go through the slit groove of the slat 4. Taken out from the slit of the slat 4, the stopper 9 can be retracted to a position on which paper does not hit. In the retracting state, the paper entering from the front part of the slat 4 is discharged from the rear part of the slat 4 without hitting on the stopper 9, so that a worker can see a paper sample after pressure adjustment without removing the slat 4 when adjusting the pressure of the folding rollers 1, 2.