A banknote handling machine comprising: an inlet unit configured to receive banknotes inserted from outside into the machine, the inlet unit having a feeding mechanism configured to feed the inserted banknotes into the machine, the banknotes being two kinds of banknotes which are composed of standard banknotes each made from paper and hybrid banknotes each made from paper and a polymer film; a transport unit configured to transport the banknotes fed into the machine by the feeding mechanism; a recognition unit configured to recognize the kinds of the banknotes transported by the transport unit and determine whether or not the banknotes transported by the transport unit are hybrid banknotes; a storage unit (30, 40) configured to store the banknotes recognized by the recognition unit; a memory unit configured to store a maximum capacity being a number of banknotes to be stored fully in the storage unit (30, 40), the memory unit being configured to store a first maximum capacity as an initial setting value; a maximum capacity change unit configured to change the maximum capacity stored in the memory unit from the first maximum capacity to a second maximum capacity, on the basis of a proportion of a number of hybrid banknotes among the banknotes stored in the storage unit (30, 40) to a number of standard banknotes among the banknotes stored in the storage unit (30, 40), or on the basis of a difference between the number of the hybrid banknotes among the banknotes stored in the storage unit (30, 40) and the number of the standard banknotes among the banknotes stored in the storage unit (30, 40), or on the basis of the number of the hybrid banknotes among the banknotes stored in the storage unit (30, 40); and a control unit configured to control the transport unit such that a number of banknotes stored in the storage unit (30, 40) does not exceed the second maximum capacity stored in the memory unit. an inlet unit configured to receive banknotes inserted from outside into the machine, the inlet unit having a feeding mechanism configured to feed the inserted banknotes into the machine, the banknotes being two kinds of banknotes which are composed of standard banknotes each made from paper and hybrid banknotes each made from paper and a polymer film; a transport unit configured to transport the banknotes fed into the machine by the feeding mechanism; a recognition unit configured to recognize the kinds of the banknotes transported by the transport unit and determine whether or not the banknotes transported by the transport unit are hybrid banknotes; a storage unit (30, 40) configured to store the banknotes recognized by the recognition unit; a memory unit configured to store a maximum capacity being a number of banknotes to be stored fully in the storage unit (30, 40), the memory unit being configured to store a first maximum capacity as an initial setting value; a maximum capacity change unit configured to change the maximum capacity stored in the memory unit from the first maximum capacity to a second maximum capacity, on the basis of a proportion of a number of hybrid banknotes among the banknotes stored in the storage unit (30, 40) to a number of standard banknotes among the banknotes stored in the storage unit (30, 40), or on the basis of a difference between the number of the hybrid banknotes among the banknotes stored in the storage unit (30, 40) and the number of the standard banknotes among the banknotes stored in the storage unit (30, 40), or on the basis of the number of the hybrid banknotes among the banknotes stored in the storage unit (30, 40); and a control unit configured to control the transport unit such that a number of banknotes stored in the storage unit (30, 40) does not exceed the second maximum capacity stored in the memory unit.