A method of diagnosing the defective state of signal-forming chains of a bolometric detector, comprising a array of detection bolometers suspended above a substrate, each chain comprising a bolometer of said array, a circuit of electric stimulation of said chain, and a circuit (22, 28) for forming a signal according to the stimulation applied to said chain by the stimulation circuit, said method comprising: a. forming the image of a substantially uniform scene on the array of bolometers; b. applying at least a different first and second stimulations to the chains; c. reading the signals formed by the chains corresponding to the applied stimulations; and d. for each chain of a predetermined set of chains to be diagnosed: ▪ defining a neighborhood formed of chains having detection bolometers which are neighbors to the detection bolometer of said chain; ▪ calculating coefficients of a polynomial interpolating the values of the signals formed by said chain according to said at least one first and second applied stimulations; ▪ calculating, for each chain of the neighborhood of said chain, coefficients of a polynomial interpolating the values of the signals formed by said neighborhood chain according to the at least one first and second applied stimulations; ▪ calculating an average and a standard deviation of said calculated coefficients of the neighborhood chains or of the set formed of the neighborhood chains and of said chain; and ▪ diagnosing that said chain is defective if the value of said coefficients thereof is outside of margins defined according to the calculated average and standard deviation. a. forming the image of a substantially uniform scene on the array of bolometers; b. applying at least a different first and second stimulations to the chains; c. reading the signals formed by the chains corresponding to the applied stimulations; and d. for each chain of a predetermined set of chains to be diagnosed: ▪ defining a neighborhood formed of chains having detection bolometers which are neighbors to the detection bolometer of said chain; ▪ calculating coefficients of a polynomial interpolating the values of the signals formed by said chain according to said at least one first and second applied stimulations; ▪ calculating, for each chain of the neighborhood of said chain, coefficients of a polynomial interpolating the values of the signals formed by said neighborhood chain according to the at least one first and second applied stimulations; ▪ calculating an average and a standard deviation of said calculated coefficients of the neighborhood chains or of the set formed of the neighborhood chains and of said chain; and ▪ diagnosing that said chain is defective if the value of said coefficients thereof is outside of margins defined according to the calculated average and standard deviation. ▪ defining a neighborhood formed of chains having detection bolometers which are neighbors to the detection bolometer of said chain; ▪ calculating coefficients of a polynomial interpolating the values of the signals formed by said chain according to said at least one first and second applied stimulations; ▪ calculating, for each chain of the neighborhood of said chain, coefficients of a polynomial interpolating the values of the signals formed by said neighborhood chain according to the at least one first and second applied stimulations; ▪ calculating an average and a standard deviation of said calculated coefficients of the neighborhood chains or of the set formed of the neighborhood chains and of said chain; and ▪ diagnosing that said chain is defective if the value of said coefficients thereof is outside of margins defined according to the calculated average and standard deviation.