Depends where your going, depends where you are, and how far you want to travel from Chesterfield.

Jet2.com; BMI Bay, BMI, Excel, Easyjet, FlyBe; British Airways.

I could quote prices etc, but prices vary massively, depending on how early you book them, normally pay about £140 -£170 return for two adults to malaga. Sometimes cheaper.

Good luck with your searching.