A method to generate an extremely high impulsive pressure using a converging metal jet, has been developed as a purpose to achieve the high pressure above 1 TPa. The metal jet is discharged from the collision point, when a metal plate is accelerated by the detonation of an explosive and it collides with a conical concave metal block. The metal jet discharged on the concentric circle of the conical concave fly toward the center while converging and collide on the central axis, and the collided metal jets exhibit the extremely high pressure. In the present investigation, framing photographs were taken using an image converter camera to investigate the phenomenon occurred in the generator. The photographs show that the metal jets are discharged from the collision points between the metal flyer plate and conical concave block, and then, collided at the central axis. The maximum pressure obtained under vacuum was estimated about 0.83 TPa from the velocity calculated from the photographs, and the results were slightly lower than that evaluated theoretically.