A blow mold with a stationary mold half and another mold half movable relative to the stationary mold half between closed and open positions, and having a bottom mold comprising a bottom mold axis essentially perpendicular to the moving direction of the other mold half which can be moved relative to the mold halves between an engaged position and a removal position, and which can be at least positively locked with the mold halves in the engaged position and the closed position of the other mold half by at least one collar-like engaging element at the bottom mold, and a ring groove-like counterengagement structure in the mold halves, the engaging element and at least the counterengagement structure form a bayonet catch in the stationary mold half which can be actuated by relative rotary motions of the engaging element about the bottom mold axis and only linear relative movements in the direction of the bottom mold axis.