A laser scanning type observation apparatus includes a pulsed-laser oscillation means irradiating pulsed laser to an object, a detector receiving light from the object to output a detection signal, a means detecting pulsed-laser oscillation to output a synchronous signal, a circuit delaying the synchronous signal for an optional amount of time to output a trigger signal, a means sampling the detection signal in synchronization with the trigger signal, a memory storing the sampled detection signal, a setting unit capable of setting delay time for delaying the synchronous signal in two or more stages within one period of the synchronous signal, and a decision unit determining an optimum delay stage for image formation using data on intensities of the detection signal at the respective delay stages, wherein the setting means fixes delay time for delaying the synchronous signal at delay time corresponding to the delay stage determined by the decision unit.