The phrase "to use the microwave" means to operate a small kitchen appliance that quickly cooks or warms up food using electromagnetic waves. Full definition
We don't use a microwave for food, but I feel safe using it for this. (wellnessmama.com)
We don't use a microwave for several reasons: food doesn't taste as good in the microwave, plus there are concerns about radiation and loss of nutrients. (wellnessmama.com)
If using the microwave, do so in bursts of 30 seconds, stirring well in between to melt all the chocolate chips. (happyandharried.com)