A conveyor for conveying products in a vertical direction comprises a frame and a drivable conveyor belt supported by the frame and following a helical track about a central centerline. The belt is provided with movable slats having upwardly directed support faces. Inner rollers and outer rollers are present at the lower side of the belt having inner axes and outer axes of rotation, respectively, which are angled with respect to the support faces. The outer rollers are located at a larger distance from the centerline than the inner rollers. The frame is provided with a first guide face for supporting the outer rollers in an outward direction which first guide face is radially directed in the outward direction and with an upwardly directed second guide faces for supporting the belt in the upward direction, which second guide face lies at a distance from the first guide face.