An implant for supporting the spinous processes of adjacent vertebral bodies includes a first implant component and a second implant component and is transferable by moving the second implant component relative to the first implant component along a spreading direction from an introduction position into a spread position. The implant includes a locking device incorporating a locking element wherein the locking element is transferable relative to at least one implant component along a locking direction from a release position, in which the second implant component is movable relative to the first implant component in a direction opposed to the spreading direction, into a locking position in which the second implant component is locked to the first implant component. The implant also includes a securing device for securing the locking element against a movement that is directed counter to the locking direction.
