Patent ID: 7522287

Claim:
A photothermal conversion measurement apparatus for measuring a property change of a sample caused by a photothermal effect of the sample when the sample is irradiated with excitation light, the photothermal conversion measurement apparatus comprising: measurement-light-emitting means for irradiating the sample with predetermined measurement light; measurement-position-changing means for changing a measurement position at which a traveling path of the measurement light passes through an excitation section in the sample, the excitation section being excited by the excitation light; and light-measuring means for measuring the property change of the sample at each measurement position set by the measurement-position-changing means on a basis of the measurement light after the measurement light passes through the sample, wherein a phase change of the measurement light that passes through the sample is measured as the property change of the sample, wherein the measurement-position-changing means includes optical-path-changing means that changes the measurement position by changing an optical path of the excitation light, and wherein the optical-path-changing means includes first optical-path-changing means that changes an incident position and/or an incident direction of the excitation light that is incident on the sample in a direction that intersects an incident direction of the measurement light on the sample.