A manhole tester is a complicated device that is used in specialized conditions. This device is needed to examine the resistance of a manhole to deformation by the outside pressure and to detect leaks. Constructing a device that would gradually apply pressure to manholes from the outside is cumbersome and financially inefficient, therefore an alternative method was invented. Manholes are tested by creating the vacuum inside them with specialized gadgets. Sucking out the air creates a pressure difference, and a force is applied to all surfaces and joints of a manhole. This allows testing structural firmness and resistance. Pressure stabilizing inside the manhole can be a sign of a structural damage or imperfection of a manhole, and can result in leaks. These damaged places should be repaired before backfilling. After backfilling leaks are much harder to identify, and vacuum testing is far more complicated due to the excessive amounts of outside pressure created by the layer of earth.