An inventive developing roller (1) includes a roller body (5) which includes an inner layer (2) having a porous structure and an outer layer (4) of a seamless nonporous tube. The porous structure of the inner layer (2) is formed from a semiconductive rubber composition containing ethylene propylene rubber, paraffin oil and carbon black having a DBP oil absorption amount of not less than 400 cm3/100 g. The nonporous tube for the outer layer (4) contains a polyurethane thermoplastic elastomer having a type-A durometer hardness of not higher than 93, carbon black and crosslinked PMMA particles having a median particle diameter of 5 μm to 20 μm.