recepitable for microwave

What you need is a 20 amp self contained device, or SCD for short. Here is Pass & Seymour info: SCD devices The P&S number you need is a SC830-S. They are also made by Hubbell and Leviton AFAIK. If it's in an outside wall you should stick with the SCD type device as normally used in an RV. Should be available from any RV parts vendor. Note that a special tool is required to punch down the wires on the stabs at the rear of the receptacle. You can use pliers and/or large flat blade screwdriver if you are careful.

The SCD devices are also used in mobile homes and that could be another source.