membrane 2 and effectively prevents the porous filter membrane 2 from being blocked in this embodiment the maximum pore diameter of the restricting orifice of the flow restrictor 3 is preferably larger than that of the porous filter membrane 2 thus the restricting orifice of the flow restrictor 3 will not be blocked during the infiltration irrigation since the maximum pore diameter of the restricting orifice of the flow restrictor 3 is larger than that of the porous filter membrane 2 in this embodiment the porous filter membrane 2 may be directly disposed on the inner wall of the water passing chamber 1 by welding or compression joint so that the water stream flows on the porous filter membrane 2 and the wash effect is the optimum as illustrated in fig1 and 3 the flow restrictor 3 may be composed of one or more restricting orifices the flow restrictor 3 may be directly opened on the pipe wall in the range covered by the porous filter membrane 2 or the restricting orifice may be extended outside the infiltration irrigation apparatus by appropriately extending the flow restrictor 3 as illustrated in fig1 in this embodiment the sidewall of the water passing chamber 1 may be disposed with an opening.