To save space as a pump unit by separately providing a converter part and an inverter part.

A converter part 17 converting commercial AC power supply into DC and an inverter part 18 converting DC voltage outputted from this converter part 17 into AC voltage are separately arranged. A pump 11, the converter part 17 and the inverter part 18 are arranged on a common base 20. Further, the pump 11, the converter part 17 and the inverter part 18 are covered by a common pump cover 21. Thus, the converter part 17 and the inverter part 18 can be installed in an empty gap of the base 20 by separating the converter part 17 and the inverter part 18 and arranging the converter part 17 and the inverter part 18 together with the pump 11 on the base 20. Therefore, saving space as a pump unit is possible, as compared with a case in which the converter part 17 and the inverter part 18 are arranged on a common control panel.