A spacer for laminoplasty is provided, the spacer including: a first spacer fixed to an upper lamina plate in a state in which an incision surface of the upper laminate plate of a lamina plate of an incised cervical vertebrae is seated on and supported by the first spacer; and a second spacer fixed to a lower lamina plate so that an incision surface of the lower lamina plate (12) of the lamina plate of the incised cervical vertebrae is in contact with and supported by the second spacer, wherein the first spacer and the second spacer are in a coupled state in which they are not separated from each other by means of a fixed bar, while having expandable lengths with respect to each other.