A paper sheet handling machine, comprising: an upper unit having a paper sheet take-in apparatus adapted for taking therein paper sheets, one by one, from the exterior, an upper transport mechanism, at least a part of which is provided to extend in a substantially horizontal direction, and which is adapted for transporting the paper sheets taken in by the paper sheet take-in apparatus, one by one, and a recognition unit provided in the middle of the upper transport mechanism (201 a) and adapted for recognizing each paper sheet transported by the upper transport mechanism, wherein at least a part of a bottom portion of the upper unit is opened; a lower unit located below the upper unit and having a lower transport mechanism provided to receive the paper sheets transferred from the upper transport mechanism, one by one, and then further transport the transferred paper sheets, and a plurality of stacking units, each adapted for stacking therein the paper sheets transported by the lower transport mechanism (201 b) and sorted based on results obtained by the recognition unit; and a partition member provided between the upper unit and the lower unit; characterised in that the upper unit can be opened upward, in that a top face of the partition member is accessible from the exterior when the upper unit is opened upward for removal by an operator of foreign material accumulated on the top face of the partition member upon maintenance for the paper sheet handling machine, and in that an opening is provided in a bottom portion of the recognition unit, in order to enable the foreign material generated in the recognition unit to fall down onto the partition member. an upper unit having a paper sheet take-in apparatus adapted for taking therein paper sheets, one by one, from the exterior, an upper transport mechanism, at least a part of which is provided to extend in a substantially horizontal direction, and which is adapted for transporting the paper sheets taken in by the paper sheet take-in apparatus, one by one, and a recognition unit provided in the middle of the upper transport mechanism (201 a) and adapted for recognizing each paper sheet transported by the upper transport mechanism, wherein at least a part of a bottom portion of the upper unit is opened; a lower unit located below the upper unit and having a lower transport mechanism provided to receive the paper sheets transferred from the upper transport mechanism, one by one, and then further transport the transferred paper sheets, and a plurality of stacking units, each adapted for stacking therein the paper sheets transported by the lower transport mechanism (201 b) and sorted based on results obtained by the recognition unit; and a partition member provided between the upper unit and the lower unit; characterised in that the upper unit can be opened upward, in that a top face of the partition member is accessible from the exterior when the upper unit is opened upward for removal by an operator of foreign material accumulated on the top face of the partition member upon maintenance for the paper sheet handling machine, and in that an opening is provided in a bottom portion of the recognition unit, in order to enable the foreign material generated in the recognition unit to fall down onto the partition member.