An object of the present invention is to provide an illuminating device for living organisms that generates artificial light with a simple configuration. An LED circuit having a plurality of LED elements that generate artificial light to irradiate a living organism, and an LED current generated by controlling an LED current supplied to the LED circuit by receiving an AC current from an AC power supply. A stimulus amount control circuit for controlling the intensity of artificial light to be emitted, and a rectifier circuit for rectifying the output current of the stimulus amount control circuit. A lighting apparatus for biological growth that is changed according to the period and the second period and further changes the change based on the frequency of the AC power source. [Selection] Figure 8【課題】簡単な構成で人口光を発生する生物育成用照明装置を提供すること。【解決手段】生物に照射する人工光を発生する複数個のＬＥＤ素子を有するＬＥＤ回路と、交流電源からの交流電流を受けて上記ＬＥＤ回路へ供給するＬＥＤ電流を制御して前記ＬＥＤ素子が発生する人工光の強度を制御する刺激量制御回路と前記刺激量制御回路の出力電流を整流する整流回路とを備え、 生物に照射する人工光の強度を直列接続されたＬＥＤ素子の数に従って第１期間と第２期間とに従って変化させ、更に上記変化を交流電源の周波数に基づいて変化させるようにした生物育成用照明装置。【選択図】図８
