The invention relates to a measuring probe for measuring the thickness of thin layers with a housing, having at least one sensor element, which is received in the housing at least slightly moveably along a longitudinal axis and which comprises at least one winding device, which is allocated to the longitudinal axis, having a spherical positioning cap facing the outer front face of the housing, said cap being arranged in the longitudinal axis, wherein the spherical positioning cap has a basic body that has a cylindrical core section and a pole cap arranged on a front face of the core section, wherein the winding device is allocated to the spherical positioning cap, said winding device being formed from a discoidal or annular carrier with at least one Archimedean coil arranged thereon and with the basic body consisting of a ferritic material and the pole cap consisting of a hard metal.