To provide a monitoring device for sludge scraper capable of effectively detecting inconveniences of a sludge scraper and a monitoring method.SOLUTION: A monitoring device of a sludge scraper includes: a pair of endless chains that pivotally support with a connection shaft a plurality of chain links to which a plurality of flight bodies are fixed at regular intervals and are connected endlessly; and a plurality of wheels which are arranged in a sedimentation basin and scrapes with the flight bodies sludge disposed on a pond bottom by circulating and driving the endless chains laid out. The monitoring device is provided with a detection part detecting rotary operation of the pair of endless chains. The detection part compares a detection pattern of the sensor detecting the chain links with a detection pattern of the chain links during normal operation stored to a storage part in advance, and detects a change of the endless chains on the basis of a result of comparison.SELECTED DRAWING: Figure 7