To provide an electrode plate mounting structure capable of eliminating the need of various types of welding means, and at the same time, ensuring a proper connection and a fixed state as well as long-term maintainability.

Regarding an electrode plate mounting structure for connecting an electrode pate 6 to a substrate 4, the end of the electrode plate 6 is laid at such a position as superposed on the end 5 of the substrate 4. Also, the end of the electrode plate 6 is bent toward the substrate 4 to form an insertion piece 6a. The substrate 4 has a mounting hole 5a for conductive connection at a position faced to the insertion piece 6a of the electrode plate 6, and the insertion piece 6a of the electrode plate 6 is pressed in the mounting hole 5a of the substrate 4. The insertion piece 6a has an engagement hole 6c, and the portion of the substrate 4 corresponding to the mounting hole 5a is placed on a support body 7. This support body 7 has a projection 7a to be coupled to the engagement hole 6c of the insertion piece 6a of the electrode plate 6, and the insertion piece 6a of the electrode plate 6 is pressed in the mounting hole 5a of the substrate 4, thereby coupling the projection 7 of the support body 7 to the engagement hole 6c.