To provide a temperature controller that allows an easy reference temperature adjustment dispensing with a skilled operator's use of a special tool.

The temperature controller has a mounting bracket 210 on which a nut 209 is fixed so as to be turned with a fixed force or larger, a setting screw 208 axially movable with turning relative to the nut 209, a lock plate 206 for holding one end of the setting screw 208, an indicator 204 representative of a pointer 205 fixed to the lock plate 206, and a setting knob 202. The nut 209 is turned for adjustment such that the pointer 205 points to a setting groove 211 at a reference temperature.