A method of evaluating a focus control of an extreme ultraviolet (EUV) lithography apparatus includes preparing a wafer exposed by using the EUV lithography apparatus. The wafer includes test patterns formed of a photoresist and having circular islands or holes prepared by multiple exposures of EUV at different foci of exposure. The method further includes measuring a roughness parameter of the test patterns and estimating a function representing a dependence of the roughness parameter on the focus. A best focus is estimated based on an extremum of the function. Exposure wafers are then exposed to EUV with the best focus. The exposure wafers include the test patterns. The roughness parameter for the test patterns on the exposure wafers obtained by exposing the exposure wafers at the best focus is periodically measured. An abnormality in focus is then determined based on the measured roughness parameter and the function.