The invention relates to a pump device having a pump (8) and an energy supply device (5, 18), wherein the pump has a conveying element (9, 11) which conveys a fluid by means of supplied energy, wherein the pump has a transport state and an operating state, and wherein at least one first element (9, 9a, 10, 10′, 11) of the pump has a different shape and/or size in the transport state than in the operating state. The operating safety of such a pump device is increased by a detection device (12, 20, 21, 22, 23, 24, 25, 27, 28, 29) which detects whether at least the first element is in the operating state with respect to shape and/or size by means of a sensor.