Provided are a charge trap evaluation method and semiconductor device including, in an embodiment, a step for applying an initialization voltage that has the same sign as a threshold voltage and is greater than or equal to the threshold voltage between the source electrode 15 and drain electrode 16 of a semiconductor device 1 having an HEMT structure and the substrate 10 of the semiconductor device 1 and initializing a trap state by forcing out trapped charge from a trap level and a step for monitoring the current flowing between the source electrode 15 and drain electrode 16 after the trap state initialization and evaluating at least one from among charge trapping, current collapse, and charge release.