Method for measuring shape of wavefront of optical radiation field generated by radiation source, includes: (a) setting diaphragm positions in pinhole diaphragm having diaphragm opening movable transversely to radiation source's optical axis, wherein a partial beam from radiation field passes through diaphragm opening at each diaphragm position and is imaged on optical sensor by imaging optics device; (b) recording lateral positions of partial beam relative to optical axis of imaging optics device, wherein lateral positions each with one of the diaphragm positions of pinhole diaphragm are recorded by optical sensor, and determining the shape of wavefront from recorded lateral positions of partial beam, wherein beam incidence range of the partial beam which is invariable for all diaphragm positions is set on imaging optics device with a pentaprism arrangement including at least first pentaprism and positioned between pinhole diaphragm and imaging optics device. A wavefront shape measuring device is also described.