Abstract: A multifunctional printer and an automatically opening or closing cover device are provided. The multifunctional printer includes a main body and the automatically opening or closing cover device. The main body includes a housing and a cover pivoted to the housing, wherein the housing includes an opening. The cover includes a first protrusion and a second protrusion protruding to the inner of the housing and being located in the opening. The automatically opening or closing cover device is disposed in the main body and includes a gear and a sliding element. The sliding element includes a body portion, a driving portion and a driven portion, wherein the driving portion and the driven portion are disposed on opposite sides of the body portion, and the driving portion engages with the gear.