The automatic screening unit consists of a weel realized in corrugated HDPE double wall of variable diameter according to requirements, provided with suitable reinforcements for the correct positioning and fixing of the filter screw screen, a tube incoming connection flanged internally that goes to engage with the loading mouth of the cochlea filter, a connecting pipe for discharge of wastewater treated. The filter screw is a integrated machine constituted by a sieve, a cochlea and a press. The materials gratings that gradually accumulate on the bottom of the screen, when the cochlea is activated, are lifted and subjected to compacting and drying up to be started outside and collected in a removable container (not included in the case of version with external collection), to then be disposed of according to the type.