A retarding potential type energy analyzer including a front grid electrode, reference grid electrode and rear grid electrode sequentially arranged, with a predetermined amount of potential difference given between the reference grid electrode and the front grid electrode to form an upward potential gradient as well as a potential difference given between the reference grid electrode and the rear grid electrode to form a downward potential gradient, the grid electrodes are arranged so that the distance between the reference grid electrode and the rear grid electrode is shorter than the distance between the reference grid electrode and the front grid electrode, or the potential difference between the reference grid electrode and the rear grid electrode is made to be greater than the potential difference between the reference grid electrode and the front grid electrode.