The present invention provides a method for measuring easily and with high accuracy the amount and the direction of decentering of an aspherical surface of an aspherical lens and a device for measuring them. The measuring device comprises: a lens receiving part; a rotating lens supporting member; a paraxial decentering measuring part, detecting the amount and direction of the decentering of a paraxial focus of both faces of the lens to be detected, relative to an axis of rotation of the member for supporting the rotating lens; a shape measuring part for a surface to be detected, detects the shape of the surface to be detected; a rotational angle measuring part, detecting the rotational angle of the lens to be detected; and an arithmetic part. In the arithmetic part, data, which is obtained by the part for measuring the shape of the surface to be detected by rotating the lens to be detected, is compared with design formulas of the surface to be detected, and the amount of relative shift and tilt, which make difference of them to be the smallest, are calculated. A position of the top of the surface relative to the axis of the rotation is calculated from the amount of the shift and tilt. The amount of the tilt and the direction of an aspherical axis relative to an optical axis of the lens to be detected, are calculated from the position of the top of the surface and the amount and direction of the decentering of the paraxial focus of the both faces of the lens to be detected, measured by the parts for measuring the paraxial decentering.