The housing G of a downpipe filter A, which housing is to be mounted between downpipe ends 1, 2, has an exteriorly oriented outlet 6, an inner sieve device 32 and a collecting trough 27 communicating with the outlet 6, upper and lower housing parts 3, 4 each comprising a mounting socket S1, S2 for square downpipe ends 1, 2, and a housing intermediate section 5 at which the outlet 6 is provided and which housing intermediate section 5 is rotatable in relation to the housing parts 3, 4 about a housing axis X.