To provide a waterproof structure suitable for an operation panel of a non-portable electronic apparatus such as an image forming device.

A rubber key 17 is arranged to cover an upper side of a circuit substrate 15, and a first skirt part 17C extending on a lower side than the circuit substrate 15 is provided at a portion of the rubber key 17 corresponding to an outer edge 15A of the circuit substrate 15 to cover the outer edge 15A. Furthermore, a groove part 23A extending along a lower end of the first skirt part 17C is provided at a lower side of the first skirt part 17C. Thereby, an upper side of the circuit substrate 15 is covered with the rubber key 17, and therefore, the circuit substrate 15 is not directly immersed with water, and the circuit substrate 15 is protected from the water. Even if the operation panel 13 is immersed with water, the water does not flow to the circuit substrate 15, is introduced to the lower side than the circuit substrate 15 by the first skirt part 17C, and then, is collected at the groove part 23A and drained.