Abstract: An evaluation device and an evaluation method for detecting quality of concrete structures comprising a conductive impact device, a sensing film, a receiver, an operation device and an auxiliary circuit, the device and the method is characterized by calculating a penetration time of the conductive film before measuring the depth of a crack in the concrete, and the evaluation work which conventionally requires dual receivers only needs now a single receiver for completion of the work. Therefore, cost and works for evaluation and signal analysis are reduced; this largely enhances the evaluation efficiency and technical level.