What to do if I only want to study master not PHD with a professor
I would focus most of the meeting on the professor's research, and use that time to show that you would be able to jump into research right away.  Probably the best way to do that is to


Read the professor's papers beforehand and display a sincere interest in his work.
Have an elevator pitch prepared for each of your previous projects so you can talk about them intelligently and with enthusiasm.


If the meeting goes well he should start discussing potential projects with you, and you should be actively engaged in this discussion, and ask intelligent questions.

Near the end of the meeting, inform him of your plan to do a PhD elsewhere.  It's better to be rejected by this guy upfront than to be accepted under false pretenses.  In order to go to a strong university you will need his letter of reference, and he might write you a weak letter if you deceive him.  (If he's really a jerk he might write you a weak letter specifically so you have to stay with him.)

But it's important to discuss this issue after he already wants you, and is on the verge of making you an offer.  Otherwise he has no reason to even consider you.

(If he specifically asks about your future plans, you should be honest and unapologetic.  To many professors, being ambitious is a good thing, and shows you are higher quality than the students who come in wanting to stay.)