A work processing apparatus comprising: a processing machine configured to carry out a predetermined process on a work with a die (16,17) attached to a die holder (14,15); and a carrier robot arranged in the vicinity of the processing machine and provided with a hand at a front end of a movable mechanism configured for holding an item such as the work, the movable mechanism including a robot arm and wrist, and being configured to be operated to control a position and attitude of the hand, characterized in that: the movable mechanism of the carrier robot is provided with the hand and an engaging part configured to be positioned to face the die (16,17) and to be engagable with an engaging part (16a,17a) provided at the die (16,17), wherein as the movable mechanism is operated to retract the hand that is holding the work to a not-interfering position with respect to the processing machine, the carrier robot is configured to be operated to move the engaging part arranged on the movable mechanism and facing the die (16,17) to be engaged with the engaging part (16a,17a) at the die (16,17), and the carrier robot is configured to be operated to move the die (16,17) with the engaging part arranged on the movable mechanism and facing the die (16,17) engaged with the engaging part (16a, 17a) at the die (16,17). a processing machine configured to carry out a predetermined process on a work with a die (16,17) attached to a die holder (14,15); and a carrier robot arranged in the vicinity of the processing machine and provided with a hand at a front end of a movable mechanism configured for holding an item such as the work, the movable mechanism including a robot arm and wrist, and being configured to be operated to control a position and attitude of the hand, characterized in that: the movable mechanism of the carrier robot is provided with the hand and an engaging part configured to be positioned to face the die (16,17) and to be engagable with an engaging part (16a,17a) provided at the die (16,17), wherein as the movable mechanism is operated to retract the hand that is holding the work to a not-interfering position with respect to the processing machine, the carrier robot is configured to be operated to move the engaging part arranged on the movable mechanism and facing the die (16,17) to be engaged with the engaging part (16a,17a) at the die (16,17), and the carrier robot is configured to be operated to move the die (16,17) with the engaging part arranged on the movable mechanism and facing the die (16,17) engaged with the engaging part (16a, 17a) at the die (16,17). the movable mechanism of the carrier robot is provided with the hand and an engaging part configured to be positioned to face the die (16,17) and to be engagable with an engaging part (16a,17a) provided at the die (16,17), wherein as the movable mechanism is operated to retract the hand that is holding the work to a not-interfering position with respect to the processing machine, the carrier robot is configured to be operated to move the engaging part arranged on the movable mechanism and facing the die (16,17) to be engaged with the engaging part (16a,17a) at the die (16,17), and the carrier robot is configured to be operated to move the die (16,17) with the engaging part arranged on the movable mechanism and facing the die (16,17) engaged with the engaging part (16a, 17a) at the die (16,17).