A light source apparatus includes a laser light source configured to emit laser light to illuminate an object, a light receiving section configured to output a light detection signal corresponding to a light quantity of at least part of the received laser light emitted from the laser light source, a calculation processing section configured to calculate a calculated value based on a detection value of the light detection signal outputted from the light receiving section and a correction coefficient to correct the detection value, and generate and output a signal indicating the calculated value, a determining section configured to compare the calculated value with a predetermined threshold, and a light source control section configured to control the laser light source based on the determination result obtained by the determining section.
