Some glass dishes are microwave safe and some other glass dishes are not microwave safe.
To test if the glass dish is safe for microwave use put some water in the glass dish and microwave on high for 1 to 2 minutes and if the glass gets too hot then it's not microwave safe but if it's just a bit warm then it's microwave safe.
Just make sure to keep an eye on the glass dish and if it isn't microwave safe then it will break in the microwave.
Most glass dishes that are microwave safe should say on the bottom of the glass dish as to whether or not it's safe to microwave or not.
If it doesn't say microwave safe it doesn't mean that it can't be microwaved but you just have to test it.
I've microwaved in glass dishes without any of them breaking so far so the glass dishes I have are microwave safe even though some of them do not say so.