To align and stack delivered sheets while making the number of delivery sheets per a unit time large.

Before a leading portion in a conveying direction of glossy paper intrudes into a nip part between a delivery roll 11A and a delivery roll 11B and a nip part between a delivery roll 12A and a delivery roll 12B, speeds of the delivery roll 11B and the delivery roll 12B are controlled to a speed Vs. After the glossy paper is conveyed by a certain distance, when a latter portion in the conveying direction of the glossy paper intrudes into the nip part, the rotation speeds of the delivery roll 11B and the delivery roll 12B are gradually decelerated. When a rear end portion in the conveying direction of the glossy paper intrudes into the nip part, the rotation speed is controlled to a release speed Vr slower than the speed Vs.