Method for determining the angular position of the rotor of a synchronous motor, wherein interpolation points through which an interpolation function, in particular an ellipse, is placed are ascertained from stator current-dependent characteristic curves of components of the stator flux, after which the stator flux Y generated as a model variable from the detected motor current and motor voltage values is compared with the interpolation function, and the angular position is ascertained therefrom, wherein a stator current, I_S, is determined from the detected motor current, wherein the detected stator current, I_S, is controlled towards a predetermined target stator current, I_Soll, wherein a first of the characteristic curves representing the components Y_d of the stator flux in the d-direction, i.e. in a first direction of a rotor-based coordinate system, is ascertained, wherein a second of the characteristic curves representing the components Y_-d of the stator flux in the opposite direction to the d-direction, i.e. in the opposite direction to the first direction of the rotor-based coordinate system, is ascertained, wherein a third of the characteristic curves representing the components Y_q of the stator flux in the q-direction, i.e. in the direction perpendicular to the first direction of the rotor-based coordinate system, is ascertained, wherein the first, second and third stator current-dependent characteristic curves represent the components Y_d, Y_-d and Y_q of the stator flux Y, wherein the interpolation points through which the interpolation function is placed are ascertained as values of the components Y_d, Y_-d and Y_q at the currently determined stator current, I_S, by means of the first, second and third characteristic curves, wherein an angle value, a, of the angular position, at which angular value the determined stator flux Y touches the interpolation function, is determined. wherein a stator current, I_S, is determined from the detected motor current, wherein the detected stator current, I_S, is controlled towards a predetermined target stator current, I_Soll, wherein a first of the characteristic curves representing the components Y_d of the stator flux in the d-direction, i.e. in a first direction of a rotor-based coordinate system, is ascertained, wherein a second of the characteristic curves representing the components Y_-d of the stator flux in the opposite direction to the d-direction, i.e. in the opposite direction to the first direction of the rotor-based coordinate system, is ascertained, wherein a third of the characteristic curves representing the components Y_q of the stator flux in the q-direction, i.e. in the direction perpendicular to the first direction of the rotor-based coordinate system, is ascertained, wherein the first, second and third stator current-dependent characteristic curves represent the components Y_d, Y_-d and Y_q of the stator flux Y, wherein the interpolation points through which the interpolation function is placed are ascertained as values of the components Y_d, Y_-d and Y_q at the currently determined stator current, I_S, by means of the first, second and third characteristic curves, wherein an angle value, a, of the angular position, at which angular value the determined stator flux Y touches the interpolation function, is determined. <EOS>