A bill recognizing and counting apparatus comprising: a feeding and transporting mechanism configured to feed a plurality of bills placed on a hopper to a transport path one by one and to transport the bills to a stacker or a rejecting unit; a line sensor provided at a predetermined position of the transport path to scan an image of the bills being transported; a denomination determination table in which denomination recognition data is registered for at least one currency; a denomination recognizing unit configured to recognize a denomination of the at least one currency by referring to the denomination determination table, a processing-mode switching unit configured to switch between a denomination recognition mode for the currency that has its denomination recognition data registered in the denomination determination table, and a different currency recognition mode for a currency that has its denomination recognition data not registered in the denomination determination table, characterized in that the apparatus further comprises: the different currency recognition mode being set by activating a different-currency recognizing unit according to an operator's operation or when the denomination recognition data of the first currency is not registered in the denomination table; a different-currency recognizing unit configured to compare a difference in size between a first bill and subsequent bills with an allowable range, based on at least a lengthwise size of the first bill obtained by scanning by the line sensor, when the different currency recognition mode is set, the different-currency recognizing unit being configured to recognize whether one of the subsequent bills is of the same denomination as the first bill based on a comparison result; and a control unit configured to perform control for guiding the bill, which is determined as a different denomination by the different-currency recognizing unit, to the rejecting unit or control for stopping the feeding and transporting mechanism, the control unit further being configured to perform control for counting the bill which is of the same denomination as the first bill. a feeding and transporting mechanism configured to feed a plurality of bills placed on a hopper to a transport path one by one and to transport the bills to a stacker or a rejecting unit; a line sensor provided at a predetermined position of the transport path to scan an image of the bills being transported; a denomination determination table in which denomination recognition data is registered for at least one currency; a denomination recognizing unit configured to recognize a denomination of the at least one currency by referring to the denomination determination table, a processing-mode switching unit configured to switch between a denomination recognition mode for the currency that has its denomination recognition data registered in the denomination determination table, and a different currency recognition mode for a currency that has its denomination recognition data not registered in the denomination determination table, characterized in the different currency recognition mode being set by activating a different-currency recognizing unit according to an operator's operation or when the denomination recognition data of the first currency is not registered in the denomination table; a different-currency recognizing unit configured to compare a difference in size between a first bill and subsequent bills with an allowable range, based on at least a lengthwise size of the first bill obtained by scanning by the line sensor, when the different currency recognition mode is set, the different-currency recognizing unit being configured to recognize whether one of the subsequent bills is of the same denomination as the first bill based on a comparison result; and a control unit configured to perform control for guiding the bill, which is determined as a different denomination by the different-currency recognizing unit, to the rejecting unit or control for stopping the feeding and transporting mechanism, the control unit further being configured to perform control for counting the bill which is of the same denomination as the first bill.