The vehicle air conditioning device has a first refrigeration cycle and second refrigeration cycle that have a portion of a refrigeration pathway in common, and form different heat pump cycles; a first water-refrigerant heat exchanger included in the first refrigeration cycle, exchanges heat between a low-temperature and low-pressure refrigerant and the coolant of a heat-generating member of the vehicle, and vaporizes the refrigerant; a flow rate adjustment means that adjusts the flow rate of the coolant flowing through the heat-generating member and the first water-refrigerant heat exchanger; a detection means that detects a decline in the amount of refrigerant in the first refrigeration cycle due to the inflow of the refrigerant into the second refrigeration cycle; and a control means that, when a decline in the amount of refrigerant in the first refrigeration cycle has been detected, controls the flow rate adjustment means, reducing the flow rate of the coolant.