Method for non-destructive inspection of parts for obtaining the properties and characteristics of the material of a part, comprising the following steps: - step of creating a mathematical model describing the dynamic behavior of a part to be inspected taking into account the geometry of the part to be inspected and the properties of the material at the different points of the part to be inspected represented by means of a set of parameters, - step of exciting the part to be inspected at at least one excitation point of the part to be inspected and with an excitation orientation, and - step of measuring the vibratory response of the part to be inspected at at least one measurement point and with a measurement orientation, characterised in that the method for inspection further comprises: - a step of optimizing surrounding conditions which is performed after the step of creating the mathematical model, in which the following sub-steps are performed in an iterative manner: ∘ sub-step of selecting surrounding conditions, ∘ sub-step of obtaining the modal shapes and associated characteristic values for the surrounding conditions selected in the preceding sub-step, and ∘ sub-step of calculating the sensitivity of the characteristic values obtained in the preceding sub-step of the same iteration to the properties and characteristics of the material of the part, for the surrounding conditions selected in the sub-step of selecting surrounding conditions of the same iteration, - a step of selecting modal shapes which is performed after the step of optimizing surrounding conditions in which the combinations of surrounding conditions and modal shapes for which the sensitivity of the characteristic values to the properties and characteristics of the material of the part is maximum are selected, and then - a step of selecting at least one excitation point with the excitation orientation and at least one measurement point with the measurement orientation depending on the modal shapes selected in the preceding step, the step of exciting the part then being started. - step of creating a mathematical model describing the dynamic behavior of a part to be inspected taking into account the geometry of the part to be inspected and the properties of the material at the different points of the part to be inspected represented by means of a set of parameters, - step of exciting the part to be inspected at at least one excitation point of the part to be inspected and with an excitation orientation, and - step of measuring the vibratory response of the part to be inspected at at least one measurement point and with a measurement orientation, - a step of optimizing surrounding conditions which is performed after the step of creating the mathematical model, in which the following sub-steps are performed in an iterative manner: ∘ sub-step of selecting surrounding conditions, ∘ sub-step of obtaining the modal shapes and associated characteristic values for the surrounding conditions selected in the preceding sub-step, and ∘ sub-step of calculating the sensitivity of the characteristic values obtained in the preceding sub-step of the same iteration to the properties and characteristics of the material of the part, for the surrounding conditions selected in the sub-step of selecting surrounding conditions of the same iteration, ∘ sub-step of selecting surrounding conditions, ∘ sub-step of obtaining the modal shapes and associated characteristic values for the surrounding conditions selected in the preceding sub-step, and ∘ sub-step of calculating the sensitivity of the characteristic values obtained in the preceding sub-step of the same iteration to the properties and characteristics of the material of the part, for the surrounding conditions selected in the sub-step of selecting surrounding conditions of the same iteration, - a step of selecting modal shapes which is performed after the step of optimizing surrounding conditions in which the combinations of surrounding conditions and modal shapes for which the sensitivity of the characteristic values to the properties and characteristics of the material of the part is maximum are selected, and then - a step of selecting at least one excitation point with the excitation orientation and at least one measurement point with the measurement orientation depending on the modal shapes selected in the preceding step, the step of exciting the part then being started.