In this study, the effect of the rotor slot depth of the single-phase asynchronous motor (SPAM) on the output performance was examined. Single-phase and two-pole squirrel cage asynchronous motor with run capacitor that has 96 W output power was used in analysis. SPAMs having Nema B class rotor which have variable resistance rotor slot structure, starting and steady-state operation were analyzed by 2D finite element method. The rotor bar cross sectional area and the rotor bar materials were taken as the same, and the rotor slot depth (Hs2) parameter was changed. Rotor slot structures having different depth were obtained by changing the Hs2 in the range of 3-7 mm with steps of 0.25 mm. Performance variables according to different rotor slot depths were comparatively examined as speed (n), input-output powers (Pi-Po), efficiency (η), current (I), torque (T), and power factor (PF). The magnetic flux densities (B), flux lines and current densities in the rotor bars (J) at the stator and rotor were visually presented. The Nema B class motor with the best performance values for all parameters was determined as the best model. In this model, the average speed, power factor and efficiency are 2954 rpm, 0.9 and 68.9%, respectively in steady-state operation. Magnetic flux densities (B), flux lines and current densities in rotor bars (J) at different points of the stator and rotor were examined and it was observed that they did not exceed the limit values defined in the literature.