Disclosed is a method for performing a measurement of an exposed pattern in photoresist on a substrate and an associated metrology device. The method comprises imparting a beam of measurement radiation on said exposed pattern over a measurement area of a size which prevents or mitigates photoresist damage from the measurement radiation; capturing scattered radiation comprising said measurement radiation subsequent to it having been scattered from said exposed pattern and detecting the scattered radiation on at least one detector. A value for a parameter of interest is determined from the scattered radiation.