An overcurrent protection apparatus for protecting a load circuit from an overcurrent, the load circuit including a power source, a load and a first semiconductor element disposed between the power source and the load, a first main electrode of the first semiconductor element being coupled to a positive electrode terminal of the power source and a second main electrode of the first semiconductor element being coupled to a negative electrode terminal of the power source via the load, the overcurrent protection apparatus comprising: an amplifying section that includes a non-inverting terminal which is coupled to the second main electrode of the first semiconductor element; a first resistor that includes one end which is coupled to the first main electrode of the first semiconductor element and the other end which is coupled to an inverting terminal of the amplifying section; a third resistor; a second semiconductor element that includes a first main electrode, a second main electrode and a control electrode, the first main electrode being grounded via the third resistor, the second main electrode being coupled to a point a which is a coupling point between the first resistor and the inverting terminal of the amplifying section, and the control electrode being coupled to an output terminal of the amplifying section; and a comparator that includes one input terminal and the other input terminal, the one input terminal being applied with a voltage at a coupling point (point e) between the second semiconductor element and the third resistor, and the other input terminal being applied with a determination voltage which is generated by dividing a voltage of the first main electrode of the first semiconductor element by a resistance ratio (R4:R5), characterized in that in a case where a current having a current value (V4 / m / Ron), which is obtained by dividing the determination voltage by a value (m) that is obtained by dividing a resistance value of the third resistor by a resistance value of the first resistor, by an average value (Ron) of an on-resistance of the first semiconductor element flows into the first semiconductor element and the on-resistance is larger than the average value (Ron) of the on-resistance, a current obtained by subtracting a current (ΔI1) proportional to a deviation (ΔRon) of the on-resistance from a current flowing through the first resistor at the point a is flown through the third resistor so that an output signal of the comparator is inverted. an amplifying section that includes a non-inverting terminal which is coupled to the second main electrode of the first semiconductor element; a first resistor that includes one end which is coupled to the first main electrode of the first semiconductor element and the other end which is coupled to an inverting terminal of the amplifying section; a third resistor; a second semiconductor element that includes a first main electrode, a second main electrode and a control electrode, the first main electrode being grounded via the third resistor, the second main electrode being coupled to a point a which is a coupling point between the first resistor and the inverting terminal of the amplifying section, and the control electrode being coupled to an output terminal of the amplifying section; and a comparator that includes one input terminal and the other input terminal, the one input terminal being applied with a voltage at a coupling point (point e) between the second semiconductor element and the third resistor, and the other input terminal being applied with a determination voltage which is generated by dividing a voltage of the first main electrode of the first semiconductor element by a resistance ratio (R4:R5),