PURPOSE: To continuously prepare a plate KONJAK (gel made from the starch of devil's tongue) in high efficiency by supplying KONJAK paste added with a coagulant to a conveyor and gelatinizing the paste by heating with far infrared radiation while suppressing evaporation of water.

CONSTITUTION: KONJAK paste 12 mixed with a coagulant is supplied to a conveyor 1 with a feeding apparatus 5. The paste is smoothed to a prescribed thickness by a smoothing apparatus 6 and successively introduced into a far infrared heating apparatus 2. The paste is continuously heated and gelatinized with an upper and a lower far infrared reflecting plates 3, 4 placed according to need. In the above process, the surface of the moving KONJAK is pressed with an evaporation-suppressing belt 7 to suppress the evaporation of water and with a pressing apparatus 10 to uniformize the thickness of whole KONJAK. The water-evaporation suppressing belt 7 is made of a far infrared transmitting membrane and transferred in the moving direction at the same speed as the conveyor 1. The gelatinized KONJAK web is cut with a cutting apparatus 8 to a prescribed shape to obtain the objective product 13.