Abstract: An electroerosion device having a wire electrode stretched and wound between two wire guides which performs taper machining by inclining the wire electrode, the wire guides having a guiding profile whose radius of curvature is at least equal to a value R given by the following formula ##EQU1## in which r designates the radius of the wire and .DELTA.L/L the elongation coefficient corresponding to the limit of elastic deformation of the wire electrode in consideration. Apparatus for measuring and calculating are associated with a numeric control in order to determine, as a function of a given angle of inclination, the height of the two points of inclination of the wire electrode in the wire guides.