To provide a portable hydraulic machining device which allows a tool to be smoothly restored to its non-machining position from its machining position.

A portable hydraulic machining device 10 supplies hydraulic oil force-fed from a hydraulic pump to a first oil chamber 16A and discharges hydraulic oil from a second oil chamber 16B so as to make a machining tool 18 start its machining. Moreover, the device 10 supplies the discharged hydraulic oil to the second oil chamber 16B and discharges the hydraulic oil from the first oil chamber 16A so as to make the machining tool 18 terminate its machining. Accordingly, driving force for bringing the machining tool 18 back to its non-machining position does not run short, and even when a situation in which the machining tool 18 bites or the like occurs, a hydraulic cylinder 16 smoothly resumes its operation. Consequently, an operation such that an operator manually restores the machining tool 18 to the non-machining position becomes unnecessary, and loss of work efficiency is thus resolved.