PURPOSE: To obtain diamond by compressing a metallic vessel by the electromagnetic interaction generated by supplying a heavy current to a solenoid.

CONSTITUTION: The metallic vessel 12 contg. graphite 16 is fixed to the solenoid 10. An electrical insulator 24 is engaged with the upper part of the vessel 12, and a fixing screw 26 is turned to surely fix the vessel 12 to the solenoid 10. A head 14 and the screw 26 are then connected to a power unit 30, electric energy is previously accumulated in a capacitor 32, and the electric energy accumulated in the capacitor 32 is discharged by turning off a switch 34. A current is induced by the spiral line of magnetic force generated by the solenoid 10, and a high compressive force is exerted on the vessel 12 by the electromagnetic interaction. Consequently, a superhigh pressure exceeding 10,000,000 atm is realized.