The invention relates to a method for testing analog telephone line equipment, especially for detecting defects of the filter (312) of the picked-up/hung-up detection circuit (112). According to said method, the telephone line equipment is isolated (103) from the line, the normal battery signal is applied (108) thereto, and a test signal enabling the polarity to be inverted at the input of said detection circuit is added to one of the wires (202) connecting the hybrid circuit (107) to the detection circuit (112). In order to control the operation of the filter (312), two successive steps are carried out for the frequencies lower than the cut-off frequency and for the frequencies higher than the cut-off frequency, whereby a test signal (206) with a low repetition frequency is first sent, followed by a test signal (206) with a high repetition frequency, or vice versa.