Apparatus for hydraulic testing

A hydraulic test apparatus is provided to perform accurate measurement in the artesian well occurring in a bore hole of establishment or confined aquifer by using the outside observing tube equipped outside the bore hole. A hydraulic test apparatus comprises a first packer(110) which selectively adheres closely to the inner surface of a bore hole, a supply tube(120) supplying the expanded fluid into the first packer, a guide tube(150) connected to the picking space under the first packer in order to guide the fluid existing in the picking space out of the bore hole, an outside observing tube(170) which is connected to the guide tube and accommodates the fluid, a valve unit(180) equipped between the guide tube and the outside observing tube in order to selectively block the flow channel, and a discharge unit(190) provided on the valve unit.