An electric heater 1 comprising a linear heater body 20 accommodated in a heat transfer tube 10, wherein a bent-back part 24 of the heater body 20 is formed inside the heat transfer tube 10 such that a pair of ends 26a and 26b emerge from a first-end side of the heat transfer tube 10, and the heater body 20 comprises a heating part 25 formed so as to extend along a part of the heat transfer tube 10 and a lead part 26 capable of electrically connecting the heating part 25 to the outside of the heat transfer tube 10. The electric heater 1 can be inserted into a narrow space and perform topical heating.