A method of analyzing defects in a semiconductor device includes: collecting current data by applying a test voltage to the semiconductor device; extracting data within a decrease range from the current data; dividing the current data into a first component value and a second component value using the current data and the data extracted from within the decrease range; calculating a first quality index from the first component value satisfying a first function; and calculating a second quality index from the second component value satisfying a second function that is different from the first function.