Vibration characteristics such as natural frequencies and mode shapes of Giromill-type vertical–axis wind turbines (VAWTs) with different design parameters are studied by Finite Element Method (FEM). As design parameters, length of the blade, thickness of the blade and the support distance of the blade are considered. On the other hand, local wind characteristics are considered for aerodynamic calculations. The well known commercial software package, ANSYS, is used for finite element analysis. Aerodynamic loads and centrifugal forces are taken into account in calculating the natural frequencies. In order to see the interactions of the parameters of the VAWT, seven models are obtained by modification of model I which is a reference model. Vibration characteristics of all models are found. The obtained results are presented in tabular forms.