The present invention is a brittle substrate (W) cleavage device (20) for cleaving a brittle substrate (W) along an intended cleavage line (L). The cleavage device is equipped with: a processing pedestal (3) on which the brittle substrate (W) is placed; a leading end fissure-forming unit (21) for forming a leading end fissure (41) as an initial fissure on the intended cleavage line (L) of the brittle substrate (W) at the leading end in the direction of movement when moving the brittle substrate (W); an end fissure-forming unit (22) for forming an end fissure (42) as an initial fissure on the intended cleavage line (L) of the brittle substrate (W) at the back end in the direction of movement when moving the brittle substrate (W); a laser irradiation unit (23) for irradiating laser light (C) on the brittle substrate (W); a refrigerant-spraying unit (24) for spraying a refrigerant (R) on the brittle substrate (W); and a movement means (25) for moving the brittle substrate (W) in a previously set direction with r
