To provide an instillation situation monitoring device monitoring the instillation situation and informing an operator of an abnormality immediately when the abnormality occurs.

This instillation situation monitoring device has optical detection parts 20-1 to 20-n provided on a side face of an instillation visible part of a liquid transportation set for instillation to measure droplets of instillation and a control part 21 which generates a condition signal by a storage means 21a storing an interval of instillation droplets at normal time and a comparison means 21b comparing this interval with a current interval of droplets and outputs it by adding a specific number of the detection parts 20-1 to 20-n to display an instillation situation in a display machine.