PROBLEM TO BE SOLVED: To maintenance work estimation device capable of more reliably estimating a maintenance work implemented.SOLUTION: A maintenance work estimation device that acquires operation information which indicates operation of an elevator device and estimates execution of a maintenance work for the elevator device based on the acquired operation information includes: a maintenance work database 7 that classifies a plurality of maintenance works into a plurality of superordinate maintenance works and a plurality of subordinate maintenance works included in each of the superordinate maintenance works and stores in advance reference information including information to be used for estimating execution of each of the plurality of superordinate maintenance works and information to be used for estimating execution of each of the plurality of subordinate maintenance works; and an estimation device 6 that estimates first the executed superordinate maintenance work from among the plurality of superordinate maintenance works and estimates the executed subordinate maintenance work from among the plurality of subordinate maintenance works included in the estimated superordinate maintenance work.