To provide a warming apparatus of low costs and simple structure, in which a plurality of temperature switches and a heater wire are easily fitted to a container.

A heater unit 11 is used in which the heater wire 12 is arranged in a zigzag form on the inner surface of the supporting tape area 33 of a heat transmission tape 31 made of aluminum and two TRSs 21 and 22 are disposed at positions away from the heater wire 12. The heater unit 11 is fitted to the outer peripheral surface of an inner container 3 with sufficient clearances between the respective parts of the heater wire 12 and between the TRSs 21 and 22. Since the tape 31 is interposed between the the respective parts of the heater wire and between the TRSs 21 and 22, contact between the respective parts of the heater wire and between the TRSs and falling out of them are prevented, and heat transmission efficiency is improved. Thus, the warming apparatus 1 with high thermal efficiency and accurate temperature control is provided.