Your microwave uses more power waiting on standby mode than is does heating your food. The average household uses the microwave for 10 minutes a day, the rest of the day the microwave is powering the little clock, and other internal electronic components while waiting to be used.
ON: 10 minutes x 1000 watts = 167 watt-hours
OFF: 23 hours, 50 minutes x 7 watts = 167 watt-hours
You could unplug your microwave when ever it is not in use but constantly plugging and unplugging your microwave can get tiresome. To solve this problem install a receptacle with a switch.
The switch controls the receptacle into which the microwave can be plugged in. When the microwave is not in use just turn off the switch and the microwave will no longer be on standby wasting electricity.
A Leviton 15 Amp Combination Switch-receptacle from Canadian Tire costs $8.00. Installation of the receptacle is easy. Just make sure to wire the receptacle so that the switch controls the receptacle. Follow the diagram. The jumper wire is only needed if the switched receptacle does not have a metal jumper plate.