Abstract: The present invention relates to an anti-pulmonary embolism filter of the pe made of a remanent spring effect resilient wire, characterized in that it is shaped into a spiral (1) having three non-touching turns (2, 3, 4) with the middle turn (3) having a diameter (d3) greater than the diameters (d2, d4) of the other two turns, and in that this diameter (d3) is selected to be close to the half-circumference of the vena cava in the zone where the filter is to be implanted so as to ensure that the function of holding the filter in place by flattening of the vena cava is optimized.