PURPOSE: To provide a ring-shaped tape cutter which is small enough to mount to a finger and is excellent in portability concerning a cutting jig in an adhesive tape to be used mainly for outdoor work, such as a curing tape to be used at the time of painting a building, a masking tape to be used at the time of applying a sealing agent.

CONSTITUTION: A tape cutter main body with a cutting blade 3 is attachably and detachably fixed to a fixing band 6. In addition, at the time of not using the blade 3, a cover 2 is moved to a cutting blade covering position with respect to a fixing member 1 to cover the blade 3 with the cover 2. On the other hand, at the time of using, the cover 2 is moved to a cutting blade exposing position to expose the blade 3 from the cover 2.