High‐quality, nominally undoped, low‐resistivity ZnSe thin films are grown by molecular beam epitaxy (MBE). The MBE ZnSe shows the largest peak intensity ratio of the near‐band‐edge emission to the deep center luminescence even at room temperature compared with other epitaxial techniques, which indicates the smallest concentration of complex defects in the MBE ZnSe. From the temperature dependence of electron mobility for MBE ZnSe, we obtained the mobility value as high as 6.9×103cm2/Vs. This is the highest value ever obtained in epitaxial ZnSe films and indicates the concentration of isolated charged defects as low as 1×1016cm−3.