A process cartridge has an electrophotographic photosenstive member and a conducting member disposed in contact with the electrophotographic photosenstive member and to which a voltage is to be applied. The electrophotographic photosensitive member and conducting member are supported as one unit and are detachably mountable to the main body of an electrophotographic apparatus. The electrophotographic photosenstive member has a support, and provided thereon are a charge generation layer and a charge trasport layer in this order. The charge transport layer having a thickness of from 12 .mu.m to 40 .mu.m and the conducting member has a conductive support and a covering layer provided thereon. The time constant .tau. of electric current of the conducting member is 0.1 second or shorter.