SrRuO₃ (SRO) thin films were prepared by laser ablation, and the effects of deposition conditions on the microstructure and electrical conductivity of these films were investigated by changing the substrate temperature (T_sub) and deposition atmosphere. The SRO thin films deposited on quartz substrates in a high vacuum (P=10⁻⁶ Pa) and an oxygen partial pressure (P_O2) of 0.13 Pa were amorphous, independent of T_sub. Pseudo-cubic SRO thin films were obtained at P_O2=13 Pa and T_sub>773 K. The Sr to Ru ratio increased with increasing T_sub, and free Ru was contained in SRO films prepared at P=10⁻⁶ Pa. The crystal grain coarsened with increasing T_sub and P_O2. The electrical conductivity (σ) of SRO thin films increased with increasing T_sub and P_O2, and the highest σ was obtained at T_sub=973 K and P_O2=13 Pa. The σ of SRO films mainly changed with the Sr/Ru ratio and the surface morphology. The change of σ associated with the magnetic phase transition was observed at 163 K.