Bi(‐Pb)‐Sr‐Ca‐Cu‐O thin films were prepared on MgO(100) single‐crystal substrates by electron cyclotron resonance (ECR) plasma sputtering at substrate temperatures from room temperature to 590 °C. Pb‐doped superconducting as‐grown films were obtained above 560 °C. TheTcvalues of the Pb‐doped films prepared at 570–590 °C were 58–64 K which increased with increasing substrate temperature. Pb‐undoped as‐grown films obtained at 590 °C showed superconduction (Tc=30 K), but the films obtained below 580 °C were semiconductors. The grain sizes and contents of the 37 A˚ phase (110 K phase) were increased by the Pb doping into the as‐grown Bi‐Sr‐Ca‐Cu‐O films.