the filtering device for a bidet in which a phytoncide filter unit of another embodiment is dissembled and assembled as shown in fig4 to 8 a phytoncide filter unit 350 includes a filter part 351 a body part 360 having a longitudinal through hole 365 a recess part 370 which is provided at a front side of the body part 360 to mount the filter part 351 a storage part 380 which is provided at an upper or lower portion 361 or 363 of the body part 360 to store the ingredient of phytoncide and a hole part 390 which communicatingly connects the storage part 380 and the front side of the body part 360 the filter part 351 is an unwoven fabric pad that is a rectangular deodorizing filter that contains activated carbon and zeolite the filter part has a plurality of holes 353 through which air passes and is filtered the body part 360 is of a cubic form through which the longitudinal through hole 365 extends at the center thereof the front side of the body part 360 has the recess part 370 in which the filter part 351 is mounted the recess part 370 has stepped grooves 371 and 373 at upper and.