A pump unit for supply and discharge of hydraulic fluid into and from an actuator upon receiving driving power from a driving source is provided, in which said actuator is fluidly connected to said pump unit via a hydraulic circuit. The pump unit includes an input member operatively connected to the driving source, a first hydraulic pump body operatively connected to the input member, a pump case for accommodating the first hydraulic pump body and forming a hydraulic fluid sump, and a PTO unit accommodated within the pump case. The PTO unit includes a PTO shaft supported by the pump case so as to have an end extending outward from the pump case, and a clutch mechanism for selectively enabling and disabling transmission of driving power from the input member to the PTO shaft.