An intervertebral device intended to be placed between two spinous processes (SP1, SP2) of two vertebrae. The device comprises a spacer (10) with grooves (14A, 14B) for receiving the spinous processes (SP1, SP2), and one or more elongated members (30A, 30B) for retaining the spinous processes (SP1, SP2) in said grooves (14A, 14B). The spacer (10) is provided with first and second holes (20A, 20B 22A, 22B). The device (1) further comprises a fixing pin (40A, 40B) which is moveable between unlocked and locked positions and which goes through the second hole (22A, 22B) and protrudes into the first hole (20A, 20B) in the locked position. The proximal portion (32A, 32B) of the elongated member (30A, 30B) interacts with the fixing pin (40A, 40B) so as to impede relative translation movement between the proximal portion (32A, 32B) and the spacer (10), in a first direction (D1A, D1B), when the fixing pin (40A, 40B) is in the locked position.
