To simply unseal so-called wrap film that packages quickly-prepared Chinese noodles or box lunch by a method wherein an unsealing device that is attached to and used for a packaging film for the quickly-prepared Chinese noodles or the box lunch is constructed so that the packaging film is broken for unsealing by raising the main body of the device.

The main body 1 of an unsealing device is made of rigid resin material such as vinyl chloride resin, and a raise-up knob 2 is molded, being united with the main body 1. A double-face adhesive tape 3 is stuck to the underside of the main body 1, covering a space extending from the front end 4 to a position on this side of a fingering part 7 of the main body so that fingers can be put for seizing on the fingering part 7 of the main body 1. The unsealing device is used, with its main body 1 attached by adhesive force of the double-face adhesive tape 3 to the surface at the lid-side of the packaging film for quickly-prepared Chinese noodles. On unsealing the packaging film, the raise-up knob 2 is caught by fingers and raised up and thereby the packaging film is broken and torn away.