PROBLEM TO BE SOLVED: To provide a room temperature managing device capable of reducing fuel cost while maintaining product quality with using an existing heater as it is.SOLUTION: A room temperature managing device 1 comprises: a transmitting part 300 which transmits a control signal for operation of a heater so that 24 hours are sectioned into 4 steps, and the room temperature is regulated at a designed temperature regarding to a step of the current time based on the room temperature and designed operation； an operation displaying part 200 that comprises a temperature designating part 202 which designates the designed temperatures at each of steps via a rotary knob P21； a switching time setting part 203 which sets step switching time； LED which is arranged in a plurality of circular rings patterns so as to display a step switching time and current time in a discriminated manner with its lighting state； a mode switching part 205 which switches to 48 hours mode in which step shifting is repeated per a time unit of 48 hours； and an every other day temperature designating part 206 which designates designed temperature in each steps at later 24 hours in the 48 hours mode.【課題】既存の暖房機をそのまま用い商品品質を維持しつつ燃料費を少なくできる室内温度管理装置を提供すること。【解決手段】２４時間を４ステップに区切り、室内温度と設定操作とに基づいて室内が現在時刻にかかるステップにおける設定温度となるように暖房機の運転の制御信号を送出する送出部３００を具備し、操作表示部２００が、回動ツマミＰ２１により各ステップにおける設定温度を指定する温度指定部２０２と、ステップ切替時刻を設定する切替時刻設定部２０３と、点灯状態によりステップ切替時刻と現在時刻とを区別して表示する複数の円環状に配されたＬＥＤと、４８時間を単位としてステップ推移を繰り返す４８時間モードに切り替えるモード切替部２０５と、４８時間モードの後半２４時間の各ステップの設定温度を指定する隔日温度指定部２０６と、を備えた室内温度管理装置１。【選択図】図３
