To provide a storage medium processing mechanism, in which the storage space of a storage passage 131 can be extended within a limited depth range.

An inclined part 162 is provided in a connection passage 161 which is a part of an input coin discharge passage 160 to shift the input coin discharge passage in the thickness direction of a visitor coin 5 relative to a storage and discharge passage 130, whereby a first guide passage 163 and a second guide passage 133 are formed so as to be superposed and opposed to a coin discharge port. Accordingly, compared with the case in which the first guide passage and the second guide passage are combined and connected with the coin discharge port, a second retention part can be provided forward, and the storage space of the storage passage can be extended within the limited depth range to improve the storage number of visitor coins.