To provide a testing apparatus that requires no complex calculation, takes no long time to complete testing, consumes no extra electric power and can help reduce the cost, and a control method for the testing apparatus.

A testing apparatus comprises: a servo valve 50 used for controlling a hydraulic actuator 16; a variable capacity pump 56 for supplying pressure oil from a hydraulic pressure source 54 to the servo valve 50; an accumulator 60 arranged between the servo valve 50 and the variable capacity pump 56 to supply separately stored pressure oil additionally to the pressure oil supplied from the variable capacity pump 56 to the servo valve 50; a relief valve 62 arranged between the servo valve 50 and the variable capacity pump 56 to return part of the pressure oil supplied from the variable capacity pump 56 to the servo valve 50; and a hydraulic pressure source control device 72 for controlling the pressure and flow rate of the variable capacity pump 56.