Abstract: A viewing material evaluating method includes: a brain activity measuring step of measuring a brain activity of a test subject who views a viewing material by using a brain activity measuring unit; a first matrix generating step of generating a first matrix estimating a semantic content of perception of the test subject on the basis of a measurement result acquired in the brain activity measuring step by using a first matrix generating unit; a second matrix generating step of generating a second matrix by performing natural language processing for text information representing a planning intention of the viewing material by using a second matrix generating unit; and a similarity calculating step of calculating similarity between the first matrix and the second matrix by using a similarity calculating unit.