To provide a horizontal conveyor for a laminate plate processing device used for a device capable of preventing a thin paper-like printed wiring board or a copper-plated laminate from dropping or being caught between conveyor wheels while it is horizontally conveyed, washed, or chemically treated, and capable of horizontally conveying, washing, or chemically treating the thin paper-like printed wiring board or the copper-plated laminate easily.

In the horizontal conveyor with conveyor wheels used for the laminate plate processing device, the conveyor wheels have recesses and protrusions in a circular sawtooth pattern on their surfaces.