A mould comprises a mould body (1) for forming therearound a body (60) with a body cavity which is accessible via an opening. The mould body is assembled from a set of mutually cohesive body parts (30,40). The body parts (30,40) are mutually releasable and removable from the body via the opening. An inflatable body (60) can be manufactured with the mould. The inflatable body (60) comprises a wall of elastomer material, which wall at least in an inflated state of the body bounds a body cavity accessible through a wall opening. The body is inflatable by filling the body cavity with a fluid.