To provide a card type medium processor and its control method to reduce a burden on a program developer while improving maintainability.

The card type medium processor 1 is provided with a plurality of units (card reader 3 or card stack part 4), a conveying means 5 for conveying a card type medium among the plurality of units, and a control means (main control board 200). The control means is provided with a control program storage part (storage area 205 of an EEPROM 204) for storing a control program for the plurality of units and the conveying means 5, a CPU 201, and a parameter storage part (storage part 206 of the EEPROM 204) for storing parameters including at least information on arrangement of the plurality of units. The CPU 201 refers to the parameter stored in the parameter storage part to execute the control program on receipt of a program execution command from a host device 100.