The electron in an electric field moves towards opposite charge or accelerates upwards towards positive charge.But what will be its direction after it emerges from the field?

I'm assuming that this a homework problem and they gave you the numbers to work with (strength of electric field, the electron's initial velocity and direction, etc). You need to calciulate the force of the electric fieldon the electron, and use F=ma to determine its acceleration while in the electric field. Multiply that acceleration by the amount of time it's subjected to the field and that gives you the change of velocity it experiences while in the field. So the electron started with an initial velocity, and now you've added this new velocity on top of that. If the initial velocity is perpendicular to the electric field, you end up with two perpendicular components ofvelocity, and can use vector addition to find the resulting magnitude and direction. Hope this helps!