To provide a snap-off blade case for performing linear cutting along a groove by restricting a braking direction to one direction when a cutter blade is broken along the groove for cutting.

The snap-off blade case 11 is constituted by including: a case 15 constituted of a base part 12 and a cover part 13; and a slit 62 allowing a storage space in the case 15 to communicate with an external part and into which the cutter blade 16 is inserted from a front end side to cut the cutter blade 16 by giving force in a direction to break the cutter blade. A projection member 64 for restricting the breaking direction of the cutter blade 16 is arranged close to the slit 62.