No rotation applied to my prefab

Hello guys, i maked script, that makes cube from game objects. Then i made gameobject that creates this prefabs. I tried to do some rotation to this prefab. And rotation doesn't work. Instantiate(Obj, pos1, Quaternion.Euler(angles1)); Values changed, but cube rotation actually is x0 y0 z0. I don't know what is the problem. If i connect some primitive instead of my prefab, rotation will work.