The invention discloses a panel for a paper holding device, which comprises a front panel, a rear panel and a ridge. The ridge is connected with the front panel and can be in pivot movement relativelyto the front panel around a first ridge; and the ridge is connected with the rear panel and can be in pivot movement relatively to the rear panel around a second ridge. The ridge comprises a first ridge part and a second ridge part which are mutually connected and can mutually and relatively move around a third ridge.