Visiable inner filter

The utility model discloses a viewable-interior filter, comprising a hollow body which is provided with a water inlet and a water outlet at the two ends and a filtering structure containing a filtering body which is arranged in the hollow body, wherein, the hollow body is provided with a transparent part or translucent part like mist, and can be integrated with a shower tap, a kitchen tap, a RO water purifier and etc so that the purified effect of water quality can be realized depending on the layer-by-layer filtering action of a layer separation bodies, besides, the operator also can directly view whether the filtering body of the internal filtering structure is discolored or not, accordingly whether the filtering function is degraded or invalided can be known timely, therefore the filter can keep the purified water quality constantly.