To hem a pair of vehicle body components in a short time, and to increase the degree of freedom in design of a hemming die, etc.

In a hemming press in a welding and assembly line to manufacture a pair of right and left front doors, a pair of right and left dies 24, 24 are continuously arranged at the position orthogonal to the conveying direction of a door assembly DA, a stay 23 to integrate an upper frame UF of a working device body 22A with a lower frame LF, two stays 23 are arranged at both ends on the work carry-in side while one stay is arranged at the center of the line on the work carry-out side, a hemming charge robot 21 is slidably arranged on the carry-in side corresponding to a pair of dies 24, 24, and two hemming delivery robots 26 are arranged back-to-back adjacent to the stay 23 on the carry-out side.