A chicken embryonic stem cell is established, which stably has pluripotency and an ability of being differentiated into a germ cell. For evaluating on whether or not the chicken embryonic stem cell can be applied to genetic modification technique, detection is made on a protein which serves as an indicator of the ability of being differentiated into a germ cell. This provides (i) a chicken embryonic stem cell applicable to genetic modification technique and (ii) a method for evaluation of the chicken embryonic stem cell.
