Disclosed are a cash box and a banknote processing device using the same. The cash box includes: a guiding plate, configured to guide a banknote to enter a banknote storage chamber; a pickup roller, configured to output the banknote; and a sensor, configured to detect a position of the guiding plate and a position of the pickup roller. When the guiding plate is in a banknote feeding position or the pickup roller is in a banknote pickup position, the sensor outputs a first signal. When the guiding plate deviates from the banknote feeding position and the pickup roller deviates from the banknote pickup position, the sensor outputs a second signal, wherein the first signal is different from the second signal.