Screening apparatus

A screening apparatus (1) includes two cylindrical punching metals (2A, 2B) formed with a plurality of holes (h); two coil springs (3A, 3B) formed by spirally coiling wire material (6) around an outer side of each of the two punching metals (2A, 2B); two outer cylinders (4A, 4B); two driving devices (5A, 5B); and a control device (20) that controls the two driving devices (5A, 5B). One of the two punching metals (2A, 2B) is supplied with a liquid (W1) to be treated and the other one of the two punching metals (2A, 2B) is connected to a downstream side of the one punching metal (2A, 2B) with respect to a flow of the liquid (W1) to be treated and has an inner diameter smaller than that of the one punching metal (2A, 2B). The control device (20) controls, when the wire material (6) clogs, the two driving devices (5A, 5B) to cut contaminates at each of the two coil springs (3A, 3B).