A deterioration evaluation apparatus for a secondary battery, which evaluates a degree of deterioration of the secondary battery of a hybrid vehicle including an engine that outputs a driving power, a motor that outputs a driving power, and the secondary battery configured to exchange an electric power with the motor, includes one or more processors configured to evaluate the degree of deterioration of the secondary battery based on a first relationship. The first relationship is set by using an accelerator operation amount and an operation point. The operation point includes a rotation speed of the engine and a load factor of the engine. The first relationship is a relationship between the operation point and a load on the secondary battery when the engine is operated at the operation point.