PROBLEM TO BE SOLVED: To provide a cereal grain expander which can observe a pressure guage from a front surface and can exert sufficiently practical endurance even with an inexpensive pressure guage to prevent expensiveness.SOLUTION: A cereal grain expander which produces a puffed food by throwing cereal grains into a pressure cooker 2 having a rotary cylindrical sealing lid 21 so as to be heated to retain a set pressure by a heater 4 and quickly releasing the pressure adopts the following means. In the first place, the pressure cooker is rotatably mounted on a mounting plate 3 erected on a base 1. In the second place, a rotary pipe 5 connected to the inside of the pressure cooker and rotating together with the pressure cooker and a connection fixed pipe 11 for a pressure extract port are connected via a rotary joint 12. In the third place, a pressure gauge 10 is arranged on a near front side of the mounting plate of the base. In the fourth place, the pressure gauge is connected to the connection fixed pipe.
