Abstract: This invention relates to an apparatus for measuring structures in a fingerprint or the like, comprising at least one sensor array adapted to be positioned close to, or in contact with, the surface of the fingerprint, the sensor array being adapted to measure chosen characteristics of the surface, e.g. by measuring capacitance or resistivity, at a plurality of positions. At least one sensor array comprises at least one line of sensors, adapted to measure said characteristics at chosen intervals of time, the surface having a relative movement in relation to the sensor array with a direction essentially perpendicular to the at least one line of sensors, and at least one of the outer ends of at least one sensor array protrudes towards the surface to be measured, providing an essentially U-shaped cross section in a plane perpendicular to the direction of said movement.