PURPOSE: To enable a very small abrasion loss of the groove of a sheave to be measured using simple constitution.

CONSTITUTION: A measuring device for the abrasion loss of a sheave includes a rotation calculation means 7 by which the angle or number of rotation of a sheave 1b when a main rope 1a moves a predetermined distance is calculated using a pulse generation means 1e; a storage means 8 for storing this calculated value; an arithmetic means 10 for calculating an effective diameter of the sheave according to a plurality of calculated values obtained from the rotation calculation means 7; an abrasion loss calculation means 9 for calculating the abrasion loss of the sheave 1b according to the results of the above calculation; a remaining amount calculation means 11 for calculating the remaining amount of the groove of the sheave; and a life estimation means 5 for calculating the remaining life of the sheave.