A deterioration detecting apparatus includes: a capacitor that is connected to an electric power source through a connection switch; a deterioration detection switch that is provided between the electric power source and a ground point; a charging-path forming unit that controls the connection switch and the deterioration detection switch, such that the electric power source, the capacitor, and the ground point are connected, to form a charging path for charging the capacitor; a voltage detecting unit that detects a voltage of the capacitor charged through the charging path; and a deterioration detecting unit that detects a deterioration in elements such as the capacitor positioned on the charging path, on the basis of the voltage of the capacitor detected by the voltage detecting unit.