Three antidot arrays with FeNi alloy thickness of 20, 50 and 100 nm have been patterned using magnetron sputtering followed by the electron-beam lithography and lift-off technique. Ferromagnetic resonance technique was used to study dynamic properties of the antidot arrays. These results were compared with the measurements of continuous films with the same composition and thickness. Two distinct resonant fields have been observed for the bias field aligned with the edges of the square holes. Resonance peaks shifted towards each other and eventually merged when the in-plane bias field was rotated towards diagonal of the squares. This dependence has been explained in terms of magnetostatic energy associated with the square holes. The magnitude of this effect was decreasing for the arrays with the reduced thickness. The perpendicular and lateral quantized standing spin wave modes were detected in the reference films and the antidot arrays due to the perpendicular and lateral dimensional confinements.