An optical measurement apparatus having an improved light intensity detection performance is provided. The optical measurement apparatus includes a light receiving element capable of converting a light intensity of light to be analyzed into an electrical signal; an input terminal to which the electrical signal is input; a first amplifier and a nonlinear element configuring a logarithmic amplifier; offset resistors; a switch unit; and a controller. An inverting input terminal of the first amplifier is electrically connected to the input terminal. The offset resistors have different resistance values. The switch unit can switch an offset resistor electrically connected between the voltage source and the input terminal, of the offset resistors. An offset current is input to the input terminal by the offset resistor electrically connected between the voltage source and the input terminal. The controller measures the light intensity based on an output voltage value of the first amplifier.