A device for stimulating the healing of a wound comprises a separating means having a fluid inlet and a gas outlet. The separating means may constitute a collecting container for collecting fluid pumped from the wound. A pump for applying negative pressure comprises pump head and a drive unit. The pump head is connected to the gas outlet of the separating means, and the pump head is detachably attached to the drive unit, so that in use the fluid inlet of the separating means is connected to a wound cover, e.g. via a conduit.