A clamping apparatus capable of fixing a roll film is disclosed. The clamping apparatus includes: a carrier comprising a slot; a cover positioned in the slot; and a cannelure formed between the cover and the carrier, for guiding the film inserted from the first film door to a predetermined position. The cover includes: an upper ramp, positioned on one side of the cannelure opening, for guiding the film from the first film door to the cannelure opening, wherein a first edge of the upper ramp is near the cannelure opening, and a second edge of the upper ramp is away from the slot opening and inclines to the first edge of the upper ramp.