To improve the sealability and durability of the restoration operation part of an excessive rise prevention device in an electric fryer.

A projected part 23 is provided on the entire periphery of the edge part of an opening part 20 formed on a case bottom plate part 1a and an O ring 22 is mounted on the inner side of the projected part 23. A bracket 12 to which the excessive rise prevention device 10 is attached is fixed to the case bottom plate part 1a so as to face the opening part 20 in the state of housing an elastic plate 21 inside, the elastic plate 21 is compressed and deformed in a thickness direction and brought into press contact with the O ring 22, and the opening part 20 is closed. For the restoration operation of the excessive rise prevention device 11, just a case 1 is turned to make the bottom plate 1a stand, the elastic plate 21 facing the opening part 20 is pressurized and a reset button 11 is pushed. By the projected part 23 around the opening part 20, oil intrusion into the case 1 is prevented and the degradation of the O ring 22 is suppressed. Since a structure is such that the elastic plate 21 is brought into press contact with the O ring 22, the excellent sealability and durability are demonstrated.