Microwave amperage

[ryandebny]

I wanted to hook up my microwave. I wanted to use 12-2 wire with a 20 amp breaker. Could I use a 15 amp breaker on the 12-2 wire.
Also should I have a designated line for it or could I hook it up to a to my counter plugs ( 3 in total ) one of the three is GFI?

[Speedy Petey]

If you have a dedicated space for it, or it is fixed in place it can't be one the counter circuit.

Why bother with 15A? Use a 20A breaker with #12. No reason not to.