Bellows pump device

A bellows pump device includes a control unit which, before operation of the bellows pump device is started, performs initial control in which solenoid valves are switched and pressurized air is supplied to suction-side air chambers in advance, thereby determining operation air pressures which are air pressures of the pressurized air to be supplied to the suction-side air chambers during the operation. As the initial control, the control unit outputs control commands to electropneumatic regulators so as to gradually increase the air pressures of the pressurized air to be supplied to the suction-side air chambers in advance, and when detection signals resulting from detection of expansion positions of the bellows are inputted from the proximity sensors to the control unit, the control unit determines the air pressures of the pressurized air supplied to the suction-side air chambers at that time as the operation air pressures.