To provide a toner seal which is easily positioned when mounted and facilitates the mounting operation without being fixed with a double-sided adhesive tape etc.

The toner seal has: a shaft core seal part 11 which is freely slidably in close contact with the whole periphery of an end of a shaft core 41 of a supply roll 40 which is freely rotatably in pressure contact with a developing roll 50 disposed by a toner supply port provided in a toner storage section 30 containing toner; and a main body seal part 12 which is freely slidably in close contact with a portion of an end peripheral surface of the developing roll 50 carrying the toner from the supply roll 40 to supply it to a photoreceptor drum 60, wherein both the seal parts 11 and 12 are integrally formed from a rubbery elastic body.