To provide a multistage heating furnace system which reduces an installation area in a factory and is mounted with a compact multistage heating furnace and a workpiece transport machine.

A multistage heating furnace 100 comprises a plurality of heating furnace units 100-1 to 100-10 piled up in a vertical direction. Each heating furnace unit has: an upper heater 102A and a lower heater 101A; support pipes 104A and 104B arranged on the upper heater 102A in a manner that horizontally extends; and a plurality of workpiece support rods 106 installed across the support pipes 104A and 104B. A workpiece transport machine 200A has: a workpiece transport rod 201 which is horizontally extended; a horizontal transport mechanism 205 which is connected to an end portion of the workpiece transport rod 201 and moves the same on a horizontal rail 204; and a vertical transport mechanism 207 which moves a workpiece transport machine body including the horizontal rail 204 on a vertical rail 206.