A media processor is provided with includes a conveyance channel over which a paper sheet-like medium is conveyed, and an accumulation mechanism which accumulates the medium sent from the conveyance channel, the accumulation mechanism including a guide member for guiding and accumulating the medium sent from the conveyance channel and a conveyor for catching the medium guided by the guide member against the guide member to draw the medium onto the guide member. It is thus possible to shorten times required for the preparing operation to accumulate bills and for the bill accumulating operation, and further to prevent mechanical malfunction such as bill jamming from occurring.