To provide a floor heating device improving its appearance and feel of walking while suppressing the occurrence of the wavy condition of a finished floor.

The floor heating device 1 comprises a cushion layer 2, a sheet heater 3 and the finished floor 4 built up in sequence on a base floor. The sheet heater 3 has a band plate heater body 31, conductors 32a, 32b integrally provided at both side ends of the heater body 31, and an auxiliary protruded portion 33 provided between the conductors 32a, 32b with its height being almost the same as the protrusion height of each of the conductors 32a, 32b from the heater body 31.