An endometrial ablation device and a method of manufacturing and using the device. An RF current is passed through an endometrium to heat it. An electroconductive expandable member such as a balloon is used as the medium for passing the current and causing the heating of the endometrium. The power delivered from a power source to the balloon is selectively provided to a plurality of electrode area segments on the balloon with each of the segments have a thermistor associated with it whereby temperature is monitored and controlled by a feedback arrangement from the thermistors. The selective application of power is provided on the basis of a switching arrangement which provides either monopolar or bipolar energy to the electrodes. The method of manufacturing the ablation device includes using commercially available stretchable sheet material or providing a mandrel or support base and coating the mandrel or base with an uncured emulsion. The emulsion is then cured to form a bladder-like coating. The coating is thereafter removed from the mandrel or base to form a bladder. Electrons and temperature sensors are formed on or secured to the bladder during or after the curing process and a fluid delivery tube is secured to the bladder for inflating the bladder.